If they are anything other than cast iron, fling them out. There are plenty of healthy alternatives on the market.
If they are cast and you really want to use them, Put a wire brush in your electric drill and give them a dry scrub. Wear goggles.
Apply a mixture of lard and course salt and scrub with a cloth.
Rinse.
If you really want to restore them but not actually use them, why not just recycle them? They are only saucepans.
Have a drink.