Apple Cider Vinegar is commonly shortened to "ACV" in discussions on the 'No Poo' Method.
After a while of using baking soda to clean your hair, you might find that it becomes dry. Apple cider vinegar is a natural moisturizer, so it's ideal for dry hair and scalps.
After washing and rinsing with baking soda, pour a mix of apple cider vinegar and water through your hair, and then rinse with water again. This cleanses your hair and also leaves it moisturized.
Baking soda and cider vinegar is good for people with a normal, dry or even combined scalp.