Question: how to wash your hair without shampoo or baking soda?
Answer: If you want to give baking soda a try, it's probably a good idea to just use it occasionally, e.g. when traveling or before going to the hair dresser (so they don't wash your hair with shampoo). Dissolve 1 tbsp of baking soda in 1 cup of water. Pour it over your scalp and give your scalp a good massage.