Anyone have a tip on how to loosen up a zipper. My Micheal Kors Astor bag has those double zippers and they are very tight and hard to pull easily. My husband says to use the oil that I use to lubricate my dog's grooming blades. Sounds plausable but I am afraid I would get it on the leather. Someone at work told me candle wax. How I would do that I have no idea. Anyone have an easy fix.