Try these:
- 1 tablespoon of baking soda in a glass of water, twice a day.
- bath with 2 cups borax (20-mule brand from the detergent isle) and 1 cup hydrogen peroxide
I had this same itch for YEARS, with limited success, until I discovered the above.
Sulphur-8 hair ointment actually works OK as a treatment (an early semi-success), but it is smelly, greasy, and has to be re-applied 3x-4x per day.