Anvilicious: All of the manswers based around illegal or dangerous activity will have a Don't Try This at Home warning preceding them, which goes on to outline all of the dangers with Brutal Honesty. In the case of questions that have multiple answers, one of them is always, "Don't do it, dumbass!", sometimes said word-for-word.
Nausea Fuel: This show is not above discussing bodily functions, fluids, and other such things. Often, at least one Manswer per episode features something gross or distasteful.
Narm Charm: The sheer over-the-topness helps keep the show entertaining for many people.