Karin from Naruto is often seen as such by many fans (especially the "whore" part). From the very beginning, any time she's alone with him she'll take off her glasses and go from tsun-tsun to dere-dere. Not to mention her willingness to rape him while their team mates sleep; they're understandably leery of leaving her alone with a wounded Sasuke. Ultimately subverted though in that not only does this totally fail to get Sasuke's attention, but Sasuke stabs her and tries to kill her when she gets taken hostage and becomes a burden
Trope Codifier, Sandy in Grease. Though to be fair, it also shows Danny trying to become the Varsity Good Guy to be with Sandy — still, he's extremely glad she made some changes too. The first actress to be approached for the role actually turned it down because of the Family-Unfriendly Aesop. Even worse, since they had a relationship that apparently worked before he changed to fit in with his friends.
This is parodied in a 30 second summary of Grease, "Now that you're not who you are anymore, I can love you for how I wanted you to be."
MAD Magazine's parody of Grease (titled "Cease") had fun with this aspect of the musical too.
Sandy: "In order to get the guy you love ... you have to be a slut! What a wonderful message for the youth of America!"
The 1950s (in which the film is set) actually put a good deal of value on fitting in with one's social group, and the 1970s (in which the film was made) was all about reinventing yourself to make your life better. So this is probably more what was once a family-friendly aesop corrupted by values dissonance than an actual use of this trope.
Crow: So, Mike, I learned from today's movie that Daphne was a slut, and Amy wasn't fun until she became a slut.
Mike Nelson: Well, that's the fun message of today's movie!
In the 1931 movie The Smiling Lieutenant, Maurice Chevalier's old girlfriend teaches his new, prim wife, whom he was more-or-less forced to marry, how to vamp it up, and Chevalier falls in love with her.
"I should've beat her where she beat me, in the sack." The Women.
Parodied in Kabhi Alvida Naa Khena: Dev tells Maya she has to spice things up with her husband to make her mariage work, so she shows up at their apartment dressed like a dominatrix and wielding a whip. Turns out all of her husband's friends are here to watch the football game...
Earth Girls Are Easy has an entire production number based on this trope, triggered when Julie Brown's character Candy suggests that heroine Geena Davis needs a makeover to recapture her distant (and cheating, not that they know it) boyfriend's eye:
Candy: Your beauty's fresh and wholesome, but science has a cure! The natural look is nowhere. Your hairdresser knows for sure! You've gotta learn the art of teasing, change your repertoire! All you need's a little faith and a see-through push-up bra!
In Summer Of Sam, Mira Sorvino can't please her husband, so she is forced to beg for sex tips from his ex-girlfriend to keep him from cheating.
In He's Just Not That Into You, Jennifer Connelly, in an effort to win back her cheating husband, shows up at his office in the middle of the day to seduce him. We have been given the impression that this is completely out of character for her and that their sex life is virtually non-existent—in fact, she blames herself for his cheating because of this.
Lampshaded and averted in The Untold Story. The lone female cop dresses in a slutty fashion in order to impress the men in the precinct. They are impressed but the chief tells her she looks "like a whore". She replies with "But this is the way your girlfriends dress." He quickly responds with, "But they are whores, my dear."
An interesting example in Dangerous Beauty: Marco Venier refuses to marry Veronica Franco because her family has no money for a dowry. Unable to marry well without a dowry, Veronica has no way to support herself except by becoming a courtesan, literally a whore. Marco eventually persuades her to become his mistress, and they eventually live happily ever after (his wife is less happy about that).
Subverted big time when two eventually meet at a party, post-makeovers; Scott is repulsed by Amy's new look, while Amy thinks that Scott is making fun of her by spouting random facts. They eventually discover that they liked each other they way they had been before, and when the movie ends, Amy, back to being a studious good girl, and Scott, who is letting Amy tutor him, are a happy couple.
Older Than Feudalism example from The Bible: Tamar is a better example — she literally pretended to be a prostitute in a plan that ultimately got her the son that the law, later codified in Mosaic lawnote basically, if you're a woman whose husband dies without giving you children, you marry his brother, if he has one, thereby making it still possible that you'll still have children, counted as being your deceased husband's. Onan didn't like that the children wouldn't be counted as his, so when he did it with Tamar, he pulled out before ejaculating, and was killed for it. Judah was supposed to let her marry his next son when he got old enough, but he, probably fearing that there was a curse on her, wasn't doing it even though he said he would, so she enacted the plan mentioned above, entitled her to have from Judah.
Discussed in A Brother's Price, set in a world where males are rare and secluded and very feminine by our world's standards. Jerin is approaching the age of marriage, and one of his sisters, paging through a men's fashion magazine, wants him to make himself tight-fitting pants with a codpiece. Such clothing would let prospective wives see what they were getting.
"You need some nice clothes so we can show you off and make a good match. People are saying you're not as fetching as rumored."
In the Sword of Truth, growing up, one of the young women in Richard's town tried this. By screwing his brother in front of him. It didn't work.
A number of people advise for or against it in the Wheel of Time. The most notable proponent is Berelain, who used seduction as a means to keep her tiny kingdom of Mayenne free from powerful neighbors. She tried to turn up the charm on Rand, who was mostly oblivious, and on Perrin, who was happily married. In general, genuine affection and respect win out over this trope for the good guys, and if it does work then it's a sign that the characters in question aren't protagonist material. Even the moderately-lecherous Mat is turned off by this trope.
Live Action TV
Inverted in Glee: Kurt (knowing Finn won't like it) encourages Rachel to dress like a slut to attract him. When she recreates Sandy's black outfit from Grease, Finn tells her she looks like a "sad clown hooker".
Possible example: in Robin Hood Kate dresses up as a drunken and flirty tavern wench in order to provide a distraction for a man that the outlaws are trying to con. Granted, she's not doing it specifically to get Robin's attention, but it does seem a rather interesting coincidence that the two become a couple in the very next episode.
Subverted in Todd and the Book of Pure Evil. Hannah dresses up as a sexy rocker chick, complete with a short skirt and a low-cut shirt, in order to win the affections of the main character. She then climbs in through his bedroom window and makes some rather deliberate advances toward him. Todd is weirded out by Hannah's behaviour and remains fixated on his love interest, Jenny. Later, she bemoans what she's turned herself into and switches back to her science geek wardrobe.
One episode of Married... with Children has Steve and Marcy falling out over his refusal to shave off the beard he's grown. Marcy finally wins by appearing wearing only some lacy black underwear and carrying an electric razor.
The situation is reversed with Peg. If she'd spent less time trying to be a sexpot and more time trying to be an ideal housewife (cooking, cleaning, etc,) then Al would spend a lot more love and attention on her.
This fact was highlighted in one episode where Peg, for whatever reason, had to clean up the backyard - Al watched with a Cheshire Cat Grin and, every now and then, would take Peg upstairs... something she dreaded in this case, since she was worn out from the manual labor.
I Love Lucy features several episodes where Lucy tries to sexy herself up either because she thinks Ricky is not paying enough attention to her or because she's jealous of the young women he works with. One of the "country" episodes features the husbands lusting after a sexy young girl in a tight dress (played by a pre-Jeanne Barbara Eden) so Lucy, Ethel and Grace (aka "Country Ethel") glamorize themselves to compete for their husbands' attention.
Subverted in an episode of Star Trek: The Next Generation when Picard finds himself dealing with a very seductive and sensual female claiming to be Ardra, the devil incarnate (and therefore the legal owner to an entire planet that supposedly sold their souls to her in exchange for a thousand years of peace). When Picard wakes up one night to find her in his cabin, stating that she knows he desires her, he brusquely replies, "On the contrary. I find you obvious and vulgar." To her credit, the woman immediately offers to dress in more demure clothing, before shifting to the form of Deanna Troi to offer him "forbidden fruit." Neither offer succeeds.
Degrassi: Manny did this in order to stop being seen as cute and win over a random one-shot character, but it's most remembered for helping her win over Craig.
Chris Rock had a stand-up bit based on how past relationships shape the requirements for current relationships for men and women differently: "Women can't go backwards in terms of lifestyle, while men can't go backwards sexually." Basically, Rock told the women in the audience that if their men kept insisting on kinky sex acts, it was because a previous girlfriend did it for him.
Lenny Bruce once said that men essentially want to date a slut and marry a saint. This bit was reenacted in his biopic.
Of course live musical performances of Grease follow this trope as well.
In Return to the Forbidden Planet, Miranda tries this on Captain Tempest after he sings about how she's much too young for him. "Good morrow, big boy!" It doesn't work quite the way she wants it - on the one hand, it does get the Captain's attention, but the robot Ariel has to remind her that it was her sweetness and charm that attracted the Captain to her in the first place, not a frou-frou frock.
In Legally Blonde: The Musical, the song Positive, as sung by Elle's imaginary Greek chorus of sorority sisters, encourages her to do this to win her ex-boyfriend back from his new uptight girlfriend.
Look at her, she's like a nun/Show him you are way more fun/Bust out the lap dance and you've won/You off the hizzle, G!
Keep it positive/Let out your inner freak/Keep it positive/Miss Prissy Pants won't last a week!
In the Heavy Rain level "Sexy Girl", Madison sluts herself up in order to get the attention of the man she's trying to get information from. She mentions that he likes his girls "cute, in a dumb sort of way."
In PK Comic Kate and Bo both advise Jess to act slutty to attract men's attention, Kate goes so far as to demonstrate by pulling a complete stranger with a cheesy chat up line and leaving with him.
In Questionable Content, after the Faye-Dora-Marten Love-Triangle finally collapsed, with Dora and Marten winding up together, Faye heads home to visit her mother and unwind for a bit. After telling her mother the entire story, the old lady tells her that, back in the day, she'd been stuck in a similar love-triangle with Faye's late father - and, obviously, won, resulting in the following conversation:
Faye: Yeah, but you ended up marryin' dad. How'd you get him to pick you instead of the other girl?
FayeMom: Oh, that was easy. I just put out first.
FayeMom: Well I didn't say it was EXACTLY like your situation!
Mocked mercilessly and then torn apart in Clone High's two-part finale: after a series of embarrassing makeovers from Abe and Toots, Cleo completely tarts up Joan of Arc. She hates the makeover but decides to keep it because it makes Abe say she's "hot" for the first time in the whole series. She stills ends up going to prom with JFK, because Abe is preoccupied with Cleo. Then JFK admits that he's liked her all along "even when she's not being a slutty whore" and they sleep with each other, just in time for Abe to realize he likes her and burst in on them.
At one point in Family Guy Lois took Meg out shopping, and pushed shirts that had "Porn Star" and "Sperm Dumpster" written on them. This is a comment on several things, one is the characters of Lois and Meg, but the other is the fact that such shirts really are sold to girls.
In South Park, when Stan falls in love with a substitute teacher, Wendy does this to try to win him back. She fails because the teacher does something similar herself.
Wendy does it again in the episode "Bebe's Boobs Destroy Society," getting a set of massive breast implants. However the guys have just gotten over their infatuation with boobs, so they just laugh at her.
Interestingly subverted in "Stupid Spoiled Whore Video Playset," in which the girls dress and act like, well, stupid spoiled whores, but as part of a fad that is an end in and of itself and NOT to attract male attention. In fact, the boys seem put off by the girls' new personae, and unlike the episodes where Wendy sluts herself up to attract Stan's attention, in this one she rails against the fad.
Inverted in The Grim Adventures of Billy & Mandy, where Mandy dons a similar look (complete with frizzy hair and a lollipop) to reject the new kid, 'Pif', that she's fallen in love with. Soon as he starts slobbering over her new look, he loses his air of coolness, and Mandy's able to "hate again."
Attempted by Lisa in an episode of The Simpsons when she finds out that all the other girls in her class have already gotten dates for the upcoming school dance. Lisa dons a cocktail dress and heavy makeup in an attempt to attract a partner for herself, but all the boys she approaches have already been asked by girls sporting similar looks. She then desperately asks Milhouse out, but even he has already asked someone out. As Lisa demands he change his mind, she sees her reflection in his glasses and realizes this is not the way to present herself.
The publishing genre of "Women's Magazines" (most notoriously Cosmopolitan), particularly in "First World" countries, are infamous for this trope as the main theme of a majority of their regular monthly articles.
The Islamic Ummah has "The Obedient Wives Club" with chapters, most prominently in Malaysia and also in Jordan, Indonesia, and Singapore. According to the Malaysian Chapter Spokeswoman, “Wives should welcome them with sexy clothes and alluring smiles when in the privacy of their homes.” Their Malaysian Chapter Vice-President sums it up, “If he needs sex, obey him. You must satisfy your husband. A good wife should be a whore in bed”. Public Reaction has been mixed, even in Malaysia itself.
Hotwife/cuckold couples in which the wife is a happily married, usually mature woman who freely enjoys additional "sex only" encounters with younger men with her husband's support, involvement and encouragement while he remains devoted and faithful take this trope Up to Eleven. While a hotwife is enjoying the prowess of a young stud, her husband can't wait his turn and wants to do his wife even more than before. The hotwife and her cuckold husband then end up having sex more frequently and their lovemaking lasts longer.
Try a reasonably large variety of sex partners before you settle down to your one - and - only. Don't be cowed by the term "promiscuity" - which, rightly defined, means indiscriminate sexual congress. Almost no girl, except a real prostitute who sells her favors to anyone who comes along is truly promiscuous since most girls get hundreds of of sex offers from men every year, and even if they accepted a score or more of these offers they would be far from indiscriminate in their selection. So don't surrender to the promiscuity bugaboo.