If you have really sensitive skin then these tips might help.
Use volcanic alum crystal – apply the minimum you need to be effective. A crystal will only grow in nature when the solution is pure.
If you use soap, shaving products or depilatories be sure to rinse them off thoroughly. Do not let deodorants react with other products.
Do not use a deodorant directly after shaving the underarms because if the skin is damaged it can not perform its barrier function and there will be greater than normal absorption.
Check the packaging. Don’t buy a liquid deodorant packed in aluminium bottles! We pack our crystals in cardboard, the pebbles in paper and the granules in cellophane.
Break the habit of applying deodorant and only deodorize when you really need to. For example, if you work in close proximity to people and need deodorant during the week, you might skip applying the deodorant at the weekends. Most Moroccans use alum deodorant in the summer, but don’t bother with it so much in the winter.
Wipe the deodorant off with a wet cloth before going to bed at night.
If a crystal is still to strong, then break it into small pieces and place the pebbles inside a small glass bottle with a spray mister. When alum pebbles are left in water they will only release a weak solution of alum.
If you wash the body in rhassoul clay (which has natural deodorizing and anti-microbial properties) you will become less reliant on deodorant.
Finally if you can’t get along with deodorant don’t panic. Simple daily washing with clay and wearing fresh clothes is sufficient in most circumstances.