R.J.
I can't use natural deodorant (tried several varieties because they really do smell soooo yummy)... but most I'm allergic to, and a few I've had really bad reactions to (dark scaly rashes).
As Theresa said... many "natural" ingredients/products are actually far more caustic than non-"natural" products. Arsenic & Dog Poo & are both totally natural and organic... doesn't make either safe to eat or smear on us.
The crystal, btw, is almost straight Aluminum salts. It's not aluminum chlorohydrate... but there are a whole bunch of different chemical versions of aluminum. ((I'm not a chemist... my 6 quarters f organic and inorganic chem I got by with the skin of my teeth... but the website is DEFINATELY cheating by saying that there is no aluminum chlorohydrate in them. There's aluminum salts, just not THAT aluminum salt). The older label version lists out the salts in it (as it still does overseas)... the new one here in the US just says "mineral" salts. As if we didn't know that many minerals are highly toxic... like cobalt, cadmium, lead, arsenic, thallium.