I would assume they meant "of boobs", but you present an interesting question of terminology. Unfortunately it begs the question, what exactly would we mean by "on boobs" in this context, so that we can question if "off boobs" is it's opposite?
Also, boobs. The answer to boobs is usually yes.
VBNMW was always "we want to give you a shitty candidate, you'll vote for it and you'll like it."