Combine baking soda and corn starch. Slowly mix in coconut oil and tea tree oil with a fork or mixer. Place in old deodorant stick and place in fridge ( coconut oil is liquid when the temp is around 74 degrees). Or you can just put it in a small glass or plastic jar and use your hand to apply, which I think works way better than putting in the old deodorant container, because you can put more on.
Tea tree oil is a natural anti-bacterial, anti-fungal, and anti-septic. Great for those underarms and natural cleaning products. I also like using Germ Destroyer essential oil