The No-Shampoo Method (also called co-washing) was originally popularized by a curly hair website about 8 years ago. It is a method of “cleansing” the hair without using shampoo which gained popularity after people began to recognize the dangers and drying effects the sulphates contained in most commercial shampoos can have on the hair and skin. People were looking for alternatives.
Basically, the method involves using conditioner instead of shampoo, to cleanse the hair. Sometimes baking soda is added to the conditioner, and sometimes an apple cider vinegar rinse is performed as a rinse at the end of the procedure. The procedure claims that conditioners contain enough cleansing agents to effectively clean the hair and scalp.