As I said above, I never use soap on my cast iron pans. My dad's way of cleaning was to wipe it out with a paper towel when it was still hot and then run it under some water (if needed), then put it on the stove with a bit of oil to reseason it. Many people do just fine using a mild soap and sponge, but I urge you NOT to scrub it with soap. That action will break down the seasoning you've worked so hard for. You don't want to start from scratch each time you use your pan. It would become a miserable experience and you'll hate your cast iron.