You shouldn’t preheat them (which I totally ignore for my pizza stone). You shouldn’t subject them to drastic changes in temperatures, and you are supposed to have most of the surface covered when cooking on them. But a pizza stone actually gets better over time. I don't put soap directly on it. I am not a PC consultant but I have always used soap on my stones. Do not try to scrub your pizza stone in an attempt to make it look brand-new, or think once it looks "old" it is time for a new one. I … The ceramic pizza stone is designed to perfect pizza cooking in home ovens; the baking science behind the pizza stone works just as long as the product is properly used and cared for. The porous stone absorbs anything you put on it, including soap, which would give your food an off-taste. I cracked my first Rectangle because I let it sit with water in it to loosen stuff out of it. A well-used pizza stone typically has many dark, discolored areas. I just have to get the greasy out. Right after cleaning it, I then turned around and loaded it with another cassarole that night and sure enough, it cracked. Because it is made of stone, when put in the oven, it will heat up evenly and consistently throughout. There’s a very important but simple difference between cleaning a pizza stone and washing other kitchen or grill utensils. You might be tempted to clean blackened parts of the stone with soapy water, but this will damage your pizza stone.  Because pizza stones (which are typically made of clay or, unsurprisingly, stone) are so porous, it's important that you never, ever use soap or any other chemical product on it. I have used my big “roaster” for that meal and it works beautifully. If you use it right away, the water in the stone can boil in the oven and crack the stone. Clean and remove stains with water and products recommended by manufacturers. It does not all come off and I never soak it but I do use soapy water. Your pizza stone requires special care. You are supposed to properly season them before using them. Embrace your discolored pizza stone. I guess I just have to do it. I have the old 9 X 13 rectangle baker and the stoneware baking lid – I think that may be what you have too. I put my sauerkraut in the bottom of the stone and put the pork on top (I have used pork chops, a tenderloin, and a pork roast this way) then cover with the lid. Avoid using soap to clean the stone. Using our soapstone pizza stones will not only cut your cooking time by nearly half, but will also give your pizza a unique browning and crisping that cannot be achieved with other pizza stones. It does not look like a brand new slab right out of the box. When washing your pizza stone, you want to avoid using soap. Don't Use Soap! Never use soap to clean them. The soapy water just help clean it a bit more. It seems kind of counter-intuitive to clean something without soap, but it’s for a very good reason.