you have some good points, and i appreciate the exchange
one clarification, though: i wasn't talking about the pejorative connotation of "selling your body", but rather the idea that a prostitution transaction amounts to a sale of a physical good (a body) rather than a rental of the good (and a sale of a service). to be coherent, this entails the premise that the sexual encounter leaves that good seriously and irreversibly damaged—and that the prostitute's client is not similarly damaged. indeed, a weak implication is that he benefits from the transaction
as for male prostitutes, part of the same meme-complex in many cultures is that being penetrated is what damages and degrades you; this is often bound up with ideas of male superiority, because the male role in vanilla penis-in-vagina intercourse is the role of the penetrator. in other cultural contexts, what's considered degrading is sex with men, who are of course almost always the clients of male prostitutes. but i agree that there is a lot of variation
there is also a lot of variation between people, and someone might be fertile ground for the 'purity ring' meme not because they feel that sex degrades women (or penetratees) but because it's just dirty and impure all around. this is the underlying metaphor for idioms like 'taint' (as a synonym for 'genitalia'), 'dirty joke', 'dirty old man', and so on. but you may be aware that boys wearing 'purity rings' is kind of a man-bites-dog phenomenon, rare enough to draw comment. the wikipedia article says that it became the 'focus of media attention' on the jonas brothers (the celebrities you mention)
someone who finds sex repulsive might be relationship material, but not for a conventional allosexual monogamous relationship. they could work well with an asexual partner or a polyamorous partner