I put a saddle cover on my Brooks if I ride in the rain, and stuff a plastic grocery bag underneath. Well, I carry the bag there in case I need one, but it does double duty as an under saddle cover. I've ridden for a couple of hours in driving rainstorms with this setup and my saddles remain bone dry. Fenders help, too

Proofide is a waterproofer but it's not like you're dipping the saddle in plastic when you use it. Saddle cover.