I would call for olive leaf or olive leaf extract.
How about pouring vinegar on the scalp in the middle of washing it? I believe you dilute the vinegar in 3 to 4 parts water, pour it onto the wet hair and let it sit for 1 minute before washing.
You have obviously tried a lot. Those are just the ideas I had of things that may be effective that you haven't mentioned.
Also, you might want to try the sitz bath - perhaps you are eliminating toxins UP and out (through the head) and the sitz could redirect them DOWN and out (bowels).