What about LDN? I know I'm sounding like a broken record / shill here. I've not had the chance to try it as it's not available in my country. But it's available in the US as prescription as off label and compounding chemists can often refer you to a dr that will prescribe it. I'm even considering flying to the US to try it.
I had never heard about it, but what I just read sounds great. It seems to work at a 1:100k dilution, so maybe you might get it under the guise of a D5 homeopathic remedy?