I have a cast iron dutch oven that had been belonged to my mother and I have used it for fifty years. I do wash it with dish soap, dry it thoroughly and apply a small amount of oil on the cooking surface and store in a dry place. I do not have food build up on the inside and keep it seasoned so it doesn't stick. I do use a non metal scrubber on the outside if there seems to be a build up which seems to be a part of cooking. I really like to cook in it. I might take the advice above and put it in the oven when I self-clean the oven.