Unfortunately my scalp can't handle rigid CG, so I periodically shampoo, sometimes just my scalp. You may consider decreasing the frequency you shampoo, and when you do, simply dilute the shampoo with water and concentrate on your scalp only; and cover your ends with conditioner during this process. Those squeeze bottles with the spout (that you use for hair color) are great for this. You can purchase empty ones cheaply at beauty supply stores.

edited to add: the purpose of the squeeze bottle is to directly apply your diluted shampoo mix to the scalp. I wasn't sure if that meaning came through or not...
3c-like S-waves and random curls
Fine density; medium & fine strands
Naturally very dry and very frizzy