For long-term storage, I prefer wax over oil any day of the week. Oil will run and soak into whatever's around the blade, and then it's not there to protect the blade. For best effect, I use kiwi-brand shoe polish and have never had a problem with rust on the blades. Even when out and about, the shoe polish gets smeared onto the inner surface of the sheath (leather for me!) and helps to waterproof it. It's a win-win situation for dirt cheap.