You're better off just washing/rinsing your hair with water (assuming you don't use chemicals on you hair to start with). I had a teacher in high school (Coach Rainey I think it was) tell the health class he taught that using shampoo and/or washing more than once a week was bad for you and your hair. It strips the natural oils that you pay for conditioners to put back in. This particular teacher had also survived cancer (despite being a fairly young man) and strove to eliminate chemicals from his life.
I've recently started washing with water only and it leaves my hair in the best condition. While I like the smell of the "natural" shampoos I sometimes use, I like the condition of my hair without them better. No frizzies or fly away hairs and with more lustre. It does tend to look a bit greasy after more than a couple of days so I don't agree with no more often than once a week; but cleaning your hair with just water every other day or so works great for me and I encourage everyone to give it a try. Oh, and let us know the results, please!