I posted the vinegar suggestion in reply to to the "deodorant or anti-perspirant, which is better" question. Have a read (description there) and you will see that the vinegar goes on in very minimal quantities and only for short periods as a somewhat prolonged wash-effect. My motivation is not a cash saving, although that is a nice little bonus. It definitely works and eventually only needs to be applied once every week or two in my case - in fact it can be several weeks, depending on circumstances. Think about it: people's armpits do not begin to smell until they are into their teens, only then has the colonisation by bacteria become sufficient to convert odourless sweat into waste products in sufficient quantity. On the other hand, people sweat from birth.