Fill a saucepan with 1-2 inches of water and place over low heat.
Place 2 tablespoons of coconut oil, cocoa butter, and shea butter in the glass jar and set in the saucepan.
Heat the ingredients until melted. As soon as you can stir the mixture, remove the jar from the heat, so it's not too hot for the other ingredients.
Stir in the arrowroot, baking soda, and cornstarch.
Add essential oils. Allow the deodorant mixture to sit for 5 minutes.
When the mixture is still pourable but thick enough to not be runny, fill the stick deodorant container. (Make sure the applicator is rolled all the way down, so there is room for the mixture!)
Store in a cool, dry place and apply as you would regular stick deodorant.