As someone from Texas I don't see the problem. "who's" for who is, "whose" for...well, whose.
Obama is someone who's cherry plumb cake fell out of his ass.
Obama is someone whose balls drop regularly.
Which is the correct one?
You wouldn't say Obama is someone who's balls drop regularly because that essentially means "Obama is someone who is balls drop regularly" which makes no sense. Thus, I use whose. It's the only thing that makes sense to me there so it has never felt awkward to me and I don't care about analyzing the English language.