Celebran chef Bobby Flay has shared his method of cleaning cast iron pans without soap, stating that he always makes sure the pan is "bone dry" after cleaning. This method is built upon centuries of history as soap often contained lye, which was a strong alkali cleaning agent. Most people avoid soap for convenience, but there are several other ways to thoroughly clean their cast iron. After cleaning, heat the pan over the stove on a low heat and remove all the water, which can prevent growth and keep it rust-free. An easy way to loosen food debris is to add water to your dirty pan on the stove and boil it to a boil, which will also kill any bacteria.