From what remember (translation: I might be wrong), aluminum exposure from your armpits is relatively insignificant compared to other routes such as your guts.
Regardless, I'm a deodorant man myself.. don't like the super-dry-pits that come with the anti-perspirants. If I get too stinky during the summers, I take a scientists-shower, which involves some wet wipes (disposed of in biohazard container) and a touch up with the deodorant.
Brad