Three years ago I found out I was allergic to a whole bunch of things, including corn and corn derivatives. The deodorant I was using at the time was giving me anaphylactic reactions, so I stopped using it (of course!). A friend told me about using zinc oxide. For a while I was able to use a tube of zinc oxide I got from from the local pharmacy, but after a while my sensitivity to the allergens increased and I started reacting to the ingredients in the pharmacy zinc oxide. This gave me the push to start making it myself. Zinc oxide powder (http://www.amazon.com/Zinc-Oxide-Powder-Quality-Resealable/dp/B003IGOL8U
), olive oil, and either bee's wax or shea butter is all you need. Shea butter is what I used because that's what I had on hand that I knew wasn't going to try and kill me. I tried it with some essential oils, but reacted to that, so I mixed up a plain batch. Just a dab under the arms after a shower. It lasts the better part of a week if you don't scrub it off every day with soap. I use it at most once per week. You can find recipes online for diaper rash cream, zinc oxide or sun block. Use them to figure out the basic ratios, omit all the irrelevant junk, and make something simple and pure.