Like I said, that is the point of the idiom. It's historically been used specifically towards sex work in a derogatory fashion.
However the reality of the phrase, "selling your body," is that it's true for all labor. One could argue it is especially true when it comes to something like construction work, which can be very hard on your body and impart long term health effects.
I think there's plenty of use in taking an idiom that's been used to harm others and flipping it back the other direction.