Woman washing her hair in shower with clarifying shampoo. Do you ever find that, however thoroughly you shampoo your hair, it still doesn’t feel clean? Even the best shampoos have their limits, no matter how often you wash your hair. The average shampoo is formulated to cut through a cocktail of pollution particles, daily grime and grease. But it’s not necessarily tough enough to also remove product buildup and hard water particles that accumulate on your hair over time.