I'd wager that someone will offer to do an entire body-ad in the nude or very close to it. I was in Switzerland years ago, and saw a couple painted green from head to foot each wearing nothing but a thong rollerblading through the streets of whatever city I was in (forget) advertising The Body Shop I believe it was.
With today's tech, I'm sure the same thing can be done in vivid color.
Ya, google up "bodypaint" or similar (not worksafe lol for sure) and you'll get bodypaint advertising, much of it from Europe or Australia.
I have seen paint ads at tradeshows and once at the beach at a volleyball tournement.
You gotta have the body, though, not merely area, so unfortunately I must still work for a living.