While in Bulk Barn one day I came across Crystal Deodorant Stones in the bath/soaps display. Trying to move towards products without parabens, sulfates and other harmful chemicals; I decided to give it a try. Initially the cost was a deterrent, but not after I started using it!
So "What is a Crystal Deodorant Stone?", you might ask. Well it actually crystalized natural mineral salts that kill odor causing bacteria. The deodorant is 100% natural and contain no harmful oils, perfumes, emulsifiers or aluminum chlorhydrate. The ingredients simple state "Mineral Salts". It is hypoallergenic, unscented, non-staining (little black dress approved!) and offers 24 hour protection when used on arm pits in the right condition (see comments below).
Applying this deodorant is easy! You just wet the crystal stone and apply it to your arm pits. I usually do 4 circles in my underarm area for each arm pit. It dries instantly on contact.
This deodorant works well when you don't have very hairy arm pits or have anxiety/nervousness induced sweating. When you don't have hairy arm pits it is easier for the cyrstal to work its magic because it is in closer contact with your skin and your hair folicles. I also found the sudden burst of sweating that sometime happens when you're nervous or anxious, causes the deodorant crystal not to work so well and you have to reapply it.
Other than that, it works really well. It comes in 120g size and I've been using it everyday since January and have not run out. Well worth what I paid for it! You can check out their website here.
Update On Aug 18, 2009: I forgot to add that the deodorant crystal also works on foot odor. I haven't tried it out on feet, but maybe you know someone that could benefit from its use.