Stoneware is excellent for cooking and baking since it is nonstick and cooks food evenly, as long as you take proper care of it. Here are the steps for how to clean stoneware properly.
Rinse Before First Use
Rinse your stoneware before its first use with water only.
Season your stoneware before using it. You can season your stoneware by cooking high fat foods on it (crescent rolls, bacon, biscuits, etc), or coat it with vegetable oil (not no-stick spray) prior to use. You should season your stoneware the first few times you use it until the surface looks smooth.
For regular cleaning of stoneware, simply use a plastic scraper to scrap food particles off and rinse under running water. Do not use cold water on hot stoneware - use warm or hot water instead else it may crack. Do not use soap unless you want your next meal to taste like soap. Do not put it in the dishwasher because the temperatures may make it crack and it will make your food taste like soap.
1) Well seasoned stoneware is supposed to look dark and maybe splotchy, so don't assume discoloration means that it is unclean.
2) Do not use non-stick spray on your stoneware, else it may get sticky.
3) If your stoneware does get sticky, you can use a mixture of baking soda and water to scrub it clean. You can also try cleaning stoneware using a minimal amount of soap, but you will have to reseason it again several times.
4) Do not put your stoneware in the oven on the self cleaning cycle, else you may crack the stoneware and void your warranty.