It wasn’t me, but I think it probably was @Dee - she has written out that thymol recipe before, I think. However, I am inclined to agree with @Red_Hot_Chilipepper, you are probably seeing the effects of varroa. Even if you didn’t want to treat, it wouldn’t hurt to do a sugar roll test to see if we are right. If the varroa count isn’t high, it might be worth going to all that trouble of making up the thymol emulsion. I also agree with Ed, that going treatment-free is fine if you have a lot of hives, but it may not be practical for those of us with only one or two hives. I have 2 hives at the moment, and although I have been able to be treatment-free so far, I am testing my bees for varroa. If the count gets worrying, I will be treating. If you like, I have a preference for no treatment, but I will not risk losing a colony to a treatable disease if I see a heavy infestation/infection.
This is a brilliant article. My husband has a nice Leitz microscope at home, so I am tempted to try it out. I am even tempted to get the microscope Randy Oliver recommends, to compare a $300 one with his $10,000 model! Might even make a grown man cry a little!