Sound like you're hunting in my neck of the woods with the rain. I'm not aware of anything you could spray on your clothes to help keep you dry. Here's my suggestion. Go to Wal-Mart and get a cheap rain suit. You should be able to get a Stearns brand for under 20 bucks. You may not find a camo suit but the blue or yellow ones will get you by. On Saturday morning put on a light layer of clothes, then the rain suit, then another layer of clothes. I've got a $40 dollar "plastic" suit but sure would like to have a Gore-Tex one.