The initial cost for the essential oils is high but they last a long time. Always use sea salt & try to find baking soda without aluminum at a health food store. This recipe is for a smaller size jar (see pic). Baby food jars would work great.
Baking soda base
Sea salt (couple of pinches)
Tea tree oil-20 drops
(or other flavor you like better)
Fill jar 1/2 full with baking soda. Add salt & essential oils.
Stir, then add more baking soda & stir again.
Just wet your toothbrush & dip into jar.
We have been using this for years & no cavities. It is all natural & frugal. Think of all the money you will save & your health will be better too.