Here's my two cents. My hair is also pleasing me in my seventies. Though there is less of it, it is still brown and feels nice. My secret is a non-soap natural shampoo ( from a company called Hairstory)and a little scalp massaging device they send with it. massage has really improved the condition of my scalp. I used to have sores and scaly patches and dandruff. The shampoo makes it feel nice and I am happy with it now. Only wash it two or three times a week like you. If it's working why not keep it going? It does have a mind of it's own now. Like me.