Well Black Walnut can be used topically to help with an itchy scalp, I’ve also heard of Rosemary being used in shampoo that helps with scalp issues. However, I would start in a completely different manner with some Burdock Root to help out the liver. A lot of the times the skin has issues because the liver is overloaded and it dumps what it can’t deal with onto the skin. Many times when you take care of the liver, the skin clears right up. If that didn’t work though, I would move on to trying Rosemary or Black Walnut