The question, I think, isn't whether someone from a culture influenced by the deodorant ads will find the smell of body odor offensive.

The question is whether we would find it offensive if no one had told us that our body odor was repulsive.

I could honestly go either way on this. I've seen plenty of evidence that people's reaction to odors is quite context dependent. I remember someone ruining a popular brand of cheese-flavored chip at my old office when they realized that when you asked someone to smell of chip bag with their eyes closed (and without them knowing what you would put in front of them) they'd recoil in disgust. It turns out some kinds of cheese smells indistinguishably like vomit.