My guess is that you are talking about Permethrin. It's not really a repellent (even though they sometimes call it that). It's an insecticide similar to what your exterminator might spray around your house. It's not sticky or staining and has no odor once it's dry. It's excellent stuff for ticks. I never go out in the Ozarks without having my clothes pre-treated with it. I enjoy watching ticks curl up and die after climbing on my pants or socks. You can put it on your gear if you like. It's won't damage anything.

I can't say that I've noticed it helping with mosquitos though. That's what DEET is for. Don't put that on your gear. It does bad stuff to some synthetics. Just put it on your skin.