I've always used wax, but go thin with it and get rid of any extra build up from the edges.
Residual wax streaks on a project will make stain look horrible.
If you have a real heavy rust problem, somebody sells cans of stuff you can open up and put near the tool - or with it under a cover. I think it's some kind of dessicant to pull the moisture out of the air.
Heard they work real well but have no direct experience.