reoccurance

I've read several reliable things (although can't cite references--sorry) that the thing about deoderant was an urban myth and there's absolutely no evidence of it being harmful.

The exception would be a deoderant that included toxins, but I don't know of any that do--per se. If you want to be double careful, you can always use a deoderant that has natural ingredients.

Personally, I'd focus much more on diet and exercise than personal care products, from everything I've heard and read.