I used to always seal my boots with something, SnoSeal in the old days. Now, I don't use much, keep them clean after a trip, some light leather dressing. I don't want to seal up the leather so much that it doesn't breathe, even with GoreTex on the inside of it. Count on the GoreTex for the waterproofing. I also use gaitors most of the time. If I hunted a lot where it was that wet I would use one of the new generation of rubber boots designed for hiking/hunting.