Offer to buy his kit for 0.25$ on the dollar. We can all pitch in....then send it free to the next green pool newb asking for help.To this day, he has never used his test kit. Sometimes there is nothing you can do.
The root of the problem in my opinion is "magical thinking". You simply cannot convince someone who is in the "magical thinking" paradigm to switch over to a Descartian way of knowing.. the cognitive dissonance is just too great for them to bear. This does not just apply to pool care. These are the same people who get ripped off by contractors, auto mechanics, lawyers, shysters, brokers, faith healers, etc ...
Just think how many bottles of Glenmorangie that equates to over the course of a year!