These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Duke: Let's get down to brass tacks, here... How much for the ape?
And another flashback which culminates in a men's lavatory with another druggie licking spilled LSD powder off of Duke's sleeve — just as a businessman walks in, notices the spectacle, and walks out.
Duke: With a little luck, [the businessman's] life was ruined forever — always thinking that just behind some narrow door in all of his favorite bars, men in red woolen shirts were getting incredible kicks from things he would never know.
Duke's plans for Lucy. He was joking, as what he said was mainly to alert Gonzo to just how much trouble that they could get into if they didn't lose her, and fast. It starts out horrible, suggesting that they feed her acid and let cops pay money to gang rape her. Right about the time he gets to the part about hanging pictures of Jesus all over the room while this is happening, it becomes clear that he's not seriously suggesting any of it.
Promptly followed by his description of what Lucy is likely to remember, and what she's likely to tell the authorities, about Gonzo.
Duke: All right, listen. In a few hours, she'll probably be sane enough to work herself into a towering Jesus-based rage at the hazy recollection of being seduced by some kind of cruel Samoan who fed her liquor and LSD, dragged her to a Vegas hotel room and then savagely penetrated every orifice in her body with his throbbing, uncircumcised member. (A passing hotel guest gasps in horror.)
The laundry list of drugs in the trunk of the car: "two bags of grass, seventy-five pellets of mescaline, five sheets of high-powered blotter acid, a salt shaker half-full of cocaine, and a whole galaxy of multicolored uppers, downers, screamers, laughers..."
Usually stops at the screamers and laughers, but sometimes includes, "...a quart of tequila, a quart of rum, a case of beer/Budweiser, a pint of raw ether, and two dozen amyls...."
Vindicated by History: The film was widely panned and ignored by critics when it was released as they called it just some weird road trip. It was also a box office flop (it is not easy to market a film like this). However, it became a massive cult following. People like it because of the performances of Depp and Del Toro and Gilliam's direction.