To Remove Rust
Buff the pan with a fine wire wheel of an electric drill. Crusted rust can then be dissolved by soaking the piece in a solution of equal amounts of white vinegar and water for a few hours. Don’t leave it longer than overnight without checking it. This solution will eventually eat the iron!
It is now important to neutralize and stop the action of the vinegar so it won’t continue to attack the iron. To do this, apply the oven cleaner again and let the piece soak overnight. You can also soak the piece overnight in an alkaline solution, such as washing soda, which is available in the cleaning department of most supermarkets and some hardware stores. Scrub the piece in dish detergent and hot water before seasoning.