Permethrin is most effective against ticks, they fall off any clothing sprayed with it very quickly. Ticks also tend to crawl upwards, check this next time you find one, if you transfer it on to a cloth and hang up same, it will crawl upwards, if you turn the article the tick will change course to continue upwards; this trait can be used to advantage: wear gaiters or at least tuck trousers inside socks so they continue on the outside of your trousers, preferably treated with permethrin. Cheap, effective. Deet is better for guarding against mosquitos etc, but ticks
cannot live with permethrin.
By the way, everyone who has ever eaten an organic carrot will eventually die, same as everyone bitten or not by a tick, using or not using permethrin, etc. The US military conducted extensive tests on the stuff and concluded that it could not be absorbed through the skin, hence why they use it on all their clothing. Oh, and everyone who agrees or disagrees will also meet their maker, in due course