Baking soda helps get rid of external body odor by killing the bacteria that grows in areas like underarms, breast creases, and the inner thighs. While in the shower or bath, massage a baking soda paste onto desired areas (paste recipe below). Let set for 2 or 3 minutes, then wash the area as usual.The baking soda paste will help kill the bacteria that causes the body odor, leaving the area smelling fresher longer.ow to Make Baking Soda Paste. Mix together 3 tablespoons of baking soda and 1 tablespoon of water using a spoon. Mush the mixture around in the bowl until it forms a paste. That’s it! Note: If baking soda gets into cuts or scrapes, it burns.