My favorite part was that Vance, supposedly, wrote about it in Hillbilly Elegy. Reading the book would easily solve the issue once and for all, but no one wanted to.
It's also why the AP article was retracted. They could obviously prove that it's not in the book, but like you said, it would be impossible to prove that he never, at any point in his life, when no one was around, fucked a couch.
...but also, the AP article didn't even involve reading the book. They just used Ctrl+F on key terms because, again, no one wants to actually read that book.
The fascinating thing about this is that, in context... it's still fucking weird, but for different reasons.
He's technically joking about how it makes you transition, saying it's a claim he heard from "scientists." So he wants to call men women as a misogynistic insult, but also to poke fun at the concept of scientific study. It's wrong to distinguish between gender and sex as part of evidence-based medicine and basic conscientiousness. It's cool and good if you're doing it to be a dick, though. He's got to police gender roles, but also insist that they are completely immutable based on your sex.
What a creepy weirdo.