What is the best foot deoderant product?

Sprinkling baking soda into the shoes and letting them sit overnight will do a good job of deodorizing. Empty out the baking soda before putting them back on, but if some remains it's fine. Baking soda works well and is inexpensive.

Generally shoes smell because they're too damp and the bacteria just takes off. It's a good idea to have two pairs of shoes and alternate them so that they can dry out between wearings.

I sprinkle a little baking soda into my tennis shoes after they get washed - and then a little more before they get washed. It works great - and it's cheap.

the powder thing