Cast-iron cookware is revered for its ability to withstand high temperatures and evenly distribute heat. Unfortunately, cast iron has the tendency to rust easily, and for this reason should never be washed with soap and water or placed in the dishwasher after cooking. You can restore a rusty cast-iron skillet with Coca-Cola. The citric acid in Coke and similar colas will eat away rust.
Pour enough Coca-Cola in the skillet to completely cover the rust. Allow the cola to sit overnight.
Pour out the Coke and scrub the skillet with a nylon scrubber. If this doesn't remove the rust, use a rotary wire brush.
Wash the skillet with soapy water and rinse it. Although soap and water are unsuitable for normal cleaning, they are necessary in this case to remove the rust residue and taste.
Dry the skillet thoroughly with an absorbent cloth to prevent future rust.
Season the skillet. To do this, heat the skillet over high heat and coat the inside with peanut or corn oil. Reduce the heat to low and allow the skillet to sit for 15 minutes. Repeat this procedure a second time before cooking with the skillet.