Well I've been using the Crystal deodarant for a few days now and can say that apparently....it works!
I was very skeptical at first, but it does do a good job of inhibiting the smelly bacteria in your pits. Oh, you still will sweat how you normally do; but you just won't smell. I sweat, I'm cool with that. As long as you don't smell me, I'm fine.
So for the $2 I spent at the GNC to try it out, I think it was worth it. That being said, it's NOT aluminum free. If I remember right, it has Potassium Alum, which contains aluminum. The argument on the net is that since it breaks down to a negatively-charged ion form when absorbed by the skin (which it does easily!), it is not freely absorbed by the cell membranes. Normal deodarant aluminum is absorbed because it breaks down to a positively-charged free aluminum molecule/atom. Believable? Not sure, but I think it's better at least for now...