Osma Alunotherapy Alum Deodorant Stick Travel contains 100% potassium alum.Alum crystals are a natural alternative to ordinary deodorant.They contract the pores so you sweat less.They also have an antibacterial effect, which means that there is less odor from sweat.applicationMoisten the alum stick with a little water and then apply it to clean armpits.Also suitable for use on other parts of the body, such as the hands and feet.