If you're looking for a more natural deodorant, there are a variety of options available. Deodorant stones are large, smooth crystals of potassium aluminum sulfate that must be wetted and applied like a regular deodorant stick. The difference between potassium alum and aluminum chlorohydrate is that potassium alum is a much larger molecule that's not thought to be absorbable through skin. However, if you want to completely eliminate aluminum from your armpits, there are many natural deodorants on the market. Burt's Bees, JASON, Trader Joe's, Kiss My Face and several other companies all offer aluminum-free deodorant sticks.