You can soak them in vinegar overnight. It will remove surface rust. You may need to leave them in longer if they're rusted heavily. Rinse them with warm water and baking soda, then spray them with WD40
Vinegar sure does work! I tried to for the first time 2 nights ago. I had an ashtray that looked horrible and I thought was beyond saving. The inside was all rust. I soaked it inside a big coffee can full of apple cider vinegar (all I had, I know I should have used white) and the rust fell right off. Amazing!
