Your dishes, bowls and mugs can accumulate metal marks from your silverware. Each time you stir your coffee or other liquid in your mug with a spoon, small metal marks are left on the mug's surface. The metal marks are black or gray in color, and dishwashing liquid alone won't remove the marks. You need a substance that can break up the mark without damaging the mug's surface.
Things You'll Need
2 soft, non-abrasive cloths or towels
Non-abrasive cleanser, such as Bar Keeper's Friend or Earth Friendly's Creamy Cleanser
Wipe the mug with a soft non-abrasive cloth or towel to remove any loose dust or dirt from the mug's surface.
Apply 1 tbsp. of a non-abrasive cleanser to a soft non-abrasive cloth or towel.
Rub the non-abrasive cleanser onto the metal marks on the mug. Let the non-abrasive cleanser sit for one minute.
Remove the non-abrasive cleanser from the mug with the non-abrasive cloth or towel.
Fill a sink with warm water. Add a tablespoon of dishwashing liquid to the water.
Wash the mug in the soapy water.
Rinse the mug with warm water. Dry the mug with a clean non-abrasive cloth or towel.
Repeat steps for other mugs with metal marks.
Wear latex gloves if you don't want to get your hands wet.