You could try going down to your local Health Food Shop (or equivalent). Sometimes they sell pure mineral deodorants. The mineral is in a sort of block and you wet it and rub it on. I can't remember the name (sorry) but they do exist. Boots also sell a Japanese mineral deodorant - again, can't remember the name but that one was a crystal that came in a little spray contrainer that you filled up with water. Sorry it's all a bit vague, but non-allergenic deodorants DO exist out there!