Have been using a crystal deodorant for nearly 30 years..After surgery I never used any until after chemo and radiation . I just used to keep giving my pits a wipe over throughout the day I got a moo goo deodorant in my chemo pack from them and it is very good Almost gone and I luckily found my usual rock crystal the other day. It lasts me 2 to 3 years. For quite some time I've only found the Rock crystal in liquid form and it needs to be bought more often. The solid is much better It's very good on the feet too.