If your concentrate is just permethrin, it is said to last 6 weeks or 6 washings, whichever comes first. Why do you think yours lasts 3 years?hanshi said:I spray my hunting clothes with the mixture, let them dry and am safe for the next three years.
I know permethrin can be bonded to clothing so that it lasts a lot longer, 70 washings, but that is the commercial process. Is that available as a concentrate OTC, is that what you have?
Spence