I bought a crystal deodorant more than a year ago while looking for something aluminum-free to keep me stink-free. I have found it to be cost-effective. I bought a little travel-size stick because i figured if it didn't work I wouldn't be out too much. Over a year later, with daily use, I still have at least half the stick left. I can't believe how long it has lasted. In the same amount of time, I would have bought 3-4 conventional deodorant/anti-perspirants.
When applying, the armpit needs to be wet so i put it on right out of the shower. It's not a quick "swipe swipe" like other deodorants. I usually rub it on for 10-15 secs. I figure it takes a little bit for the water to melt (?) the salts for them to be applied.
This is NOT an anti-perspirant. I still sweat, but I find it is not as much as I used to sweat even with conventional deodorant/anti-perspirants, and the sweat doesn't smell.
I found there was a "detox" period when I started to use this deodorant. I think it took my pores several days to get the yucky gunk out, to be receptive to the crystal. After those initial days (used over a long weekend), I have not noticed a stink. I often have my husband or close friend to do a smell test because I have always had a fear of being "the stinky girl".
I HIGHLY recommend the crystal deodorant.