“Shampoo? Here's What You Do   If you are interested in using baking soda for shampoo, there are several things you will need to do. You will need two tablespoons of baking soda and 500 ML of water. Stir in order to dissolve the baking soda. Wet your hair and then pour the water and baking soda mixture over your hair.   You will then need to scrub the baking soda and water mixture”