Hooo boy, you're continuing to perfectly misread me and gloss over what I'm trying to say at key points, it feels. But I'm just going to skip over the first two points instead of continue to try and clarify them seemingly fruitlessly.
It is not particularly meaningful to analyze which labor is described accurately versus not by the phrase of the idiom, because the phrase has no coherent literal meaning. Hence, the phrase is understood only idiomatically.
Let me try a different approach here since it seems I'm not communicating with you effectively.
First off, seems like we're both on the same side here: Sex work is real work, and it should be destigmarized. Cool? Cool.
The idiom, "selling your body," is derogatory phrase used to refer to engaging in sex work. It's used to separate or, "otherize," sex workers.
Pretty sure we're still on the same page.
So, actually, I guess my first question to you is if the string of words, "selling your body" has no meaning outside of the idiom, how did it come to refer to sex work specifically in the first place? Obviously it was just a figure of speech someone used first right? And their implied meaning was that there is something wrong or immoral about selling sex, and specifically sex. Which is what got rolled into the idiom.
So, bare with me, and just humor me for a minute here.
Take just the figure of speech, drop the part where it's specifically about sex work. Can you explain to me how sex work is "selling your body," so to speak, where other work isn't?