Article: Wash it by hand prior to the first use. In the future, it is not recommended that you use soap on your stoneware, or it will remove the seasoning.  It can cause a sticky surface that prevents seasoning.

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Remove the stoneware dish from the package. Dry the stoneware with a towel and set it aside. Don’t use aerosol non-stick spray on the surface of the stoneware. Wait until you have seasoned your pan initially to use it in food preparation.