I'm a big believer in M&T shampoo! I once had a live-in Mexican housekeeper that had incredibly long, thick hair. She infrequently washed her hair when she was in Mexico for lack of indoor plumbing. She rationalized that the natural oil in her hair made it healthy, but the hair odor was pretty strong. Regular shampoo didn't do a very good job of getting her hair clean...and it was rather expensive. So I used M&T on her with great results. One shampoo per week after that was enough to keep the odor under control, and it made her hair very shiny and easy to comb and brush. Twice per week in the summer.