On back pack hunts in AK, I always take some paper towels. I wad them up and place in my boots over night in the tent (after removing the insoles). This absorbs a surprising amount of moisture, but without heat and air, you're never going to get them completely dry. In the morning I'll remove the towels and hang them in the tent so they are dry and able to be re-used the next night. Typically in AK your leather boots get wet and usually stay wet regardless of using Nixwax or similar products. The leather eventually wets through. Plus my feet sweat a lot so that doesn't help matters. lol When I'm glassing and it's sunny, I'll take my boots off and let the sun and ever-present wind help dry them out.