I just picked up some boots second hand, which I wouldn't normally do, but they were $10 for a pair that usually costs well over $100. I want to disinfect them prior to wearing them, but since the inside of the bit has exposed flesh side leather, I'm unsure of what to use. I have isopropyl, which I have used before on the grain side with no I'll effects, but I'm not so sure if the same will be true here. Thanks for any advice.