Last fall the ticks here in my hunting areas were unbareable. Usually you might get one on you evey now or then but nothing to drastic, but last year I was bringing back 8 to 12 ticks a outting not counting the ones I picked off before I got home. I went to the hospital once and I think my brother went two or three times. We talked to coworker that hunts down south and he told us of his battles with ticks and how he uses a tick spray that is very effective. We told him that we were leary of the nasty chemicals that go into the making of those sprays and the possible harmful effects. He told us to spray our coats, pants, and boots outside and let them dry for a day and they would be safe to wear. We took his advice and we never saw one tick on us after that. Here is a pic of what we used. We got it a Dicks Sporting Goods. Hope they restock here because they have been sold out since deer season and my can is just about empty.
I forgot to mention that one good coat of spray last for days and I don't think wet weather weakens it. You don't have to spray every time you go in to the woods. This spray worked great for me and my brother.
Permethrin is a good insecticide. For about 15 bucks, you can get a concentrated bottle of it, use a capful in a spraybottle, fill the rest with water, and use it to spray on yourself (or for livestock, dogs, kids, plants, and just about anything).
It is an all-natural insecticide - its made from chrysanthemums.