Doubt he'll do anything tbh. They are just too busy, and there is no profit making a pill from washing powder!
As for psoriasis. Meh. I've had it nearly forty years now so pretty used to it. It's a lot better than it was when I was younger and I was never anywhere near as bad as others I have met with it. They have my sympathy. Perhaps it does work for it though? As I said, I haven't really had many outbreaks for a few years, certainly my elbows and knees are clear, no body patches, or the annoying one on the bridge of my nose between my eyebrows.
Yes there was a comprehensive study of countries with the levels of naturally appearing boron in foods against incident of RA. Basically, the more boron in the soil, the lower incidence in the population. The problem is that mass agriculture depletes soils of these trace elements, meaning the food has less in it.
http://www.positivehealth.com/article/nutrition/boron-major-cause-and-cure-for-arthritis.
I don't use Borax, I used Boron supplements. I assume they are safe (well 2 years and I haven't showed any ill effects) and it is a naturally occurring chemical.
Now, while I accept that for me it has worked and could purely be luck (I doubt that). If I have a choice between a food supplement that costs pence and has no side effects when in the trace quantities a supplement contains, and taking methotrexate which is so dangerous you have to have monthly blood tests to ensure your liver still works, and has a listed side effect of "sudden death", I think I know which one I prefer to take while it works.