Some people are allergic to permethrin. While bonded stuff is fine, loose dust is not good for them or for cat, etc. Rinsing is good.
Since the permethrin is taken up by the fabric, it doesn’t really matter all that much about concentration. .02% in a gallon is the same as .04% in a half gallon. The fabric will only bond to so much, depending on the type. You might have to leave it in the bath overnight of you get it down to .01% in two gallons, though.
You should NEVER pour excess permethrin down a drain. I wash as needed not because of permethrin. Some pants nylon pants are about 15 years old and were only treated once.
Yeah, you can look at it that way. Here in the ADK’s we don’t have a lot of ticks. I have met several people that have been treated for Lyme disease and for Rocky Mountain Spotted Fever. Nope, I don’t want these. I’ll dip, thank you.
Yeah, 10% is often diluted with petroleum products which can be bad for you. I just use ant dust at .05% and mix it with a gallon of water. Cost is about $4. The chalk helps it mix easy. It makes about 2 gallons. I Dip all my hiking cloths once for about 2 hours in a hot water bath, then hang them to dry overnight. After rinsing them, I wash them out and never have to do them again for about 8-10 years or longer.
Tics are only one problem. Mosquitoes, chiggers, bedbugs, spiders, blackflies, etc are all killed on contact with my clothing. It may take a few minutes, but they loose interest in biting fairly soon. Permethrin/DEET is my combination for the north woods in spring, often only getting 4-5 bites despite clouds of blackflies. It is also good for killing termites and other foundation insects. So, excess is also valuable for treating shelter foundations (lean-to’s, cabins, etc.)