Cast-iron cookware
Because other cookware cleaning techniques like scouring or washing in a dishwasher can remove or damage the seasoning on a bare cast-iron pan, these pans should not be cleaned like most other cookware. Some chefs advocate never cleaning cast-iron pans at all; simply wiping them out after use, or washing them with hot water and a stiff brush. Others advocate washing with mild soap and water, and then re-applying a thin layer of fat or oil. A third approach is to scrub with coarse salt and a paper towel or clean rag.
Conservation and restoration of bone, horn, and antler objects
If dusting alone is not enough, smooth materials are then cleaned with water and mild soap. A cotton swab is used to apply a soapy solution sparingly. The surface can not remain damp longer than a few seconds and will immediately be dried with a soft tissue or another cotton swab. The same area will be cleaned again in the same manner to remove any soap film. If the surface is cracked or porous, water will not be applied. Bone should never be soaked.