I have been treating my clothing with permethrin for years before venturing out on backpacking and hiking trips. I started using permethrin from Sawyer, then changed to diluting farm grade permethrin. However, now I am using a product called Duration. It is the only 10 percent concentrated permethrin that is registered with the EPA for application on clothing.
I received my Duration permethrin from The Tick Terminator (insert cheesy Schwartzenegger voice here). Duration is 50% cheaper than Sawyer and unlike the farmer grade permethrin it is approved for clothing application. The Ticker Terminator tells me application of Duration can last up to 6 months (while Sawyer lasts 6 weeks). Also, I didn't mention it in the video, but Duration does not have a strong odor like the farm grade permethrin.