Dandruff???

Hi...just wondering if anyone has any news about anything that can be used for dandruff? My husband has been using a dandruff shampoo for years and claims that it is the only thing that stops the dandruff. He just recently tried to use a biological cleanser that contains no dangerous chemicals and within a week or two, his dandruff reappeared. I told him that I'd do some research and try to find something less toxic then one of those shampoos like Selsun Blue. Any thought will be greatly appreciated. Joyce Tweet