My sister was advised to use a crystal deodorant during her breast cancer treatment because the powdery residue of other deodorants can interfere with the imaging. She liked it so much that she told me about them.
Crystal deodorants work because a thin film is distributed when you rub the crystal on your skin restoring the acid mantle of the skin which, in turn, inhibits the growth of odor-causing bacteria. Most commercial crystals are made of ammonium alum, but you can get potassium alum crystals at a health food store. Both of these compounds have been used for centuries and are considered non-toxic by the scientific community. The only problem is, like any substance, a tiny group of people could be sensitive to these particular compounds and could develop contact dermatitis.
I like the crystal deodorants because they dry in seconds after applying them without any residue, they work well for me, they are inexpensive (a crystal can last up to a year of daily use), and they are perfect for traveling since they are not subject to any restrictions. I also like that these deodorants are made of a single compound instead of a more complicated formula that includes fragrances.
