Be gentle while washing stoneware coffee mugs to prevent ruining the surface finish. A thorough rinse with warm water should be your first step in the cleaning process – this helps rid the mug of most residues. To eliminate tougher stains, mix baking soda with a small amount of water to form a paste that can be used to rub off markings that affect the glaze but are hard to remove. Extreme temperatures, caustic chemicals, and anything abrasive are also out of the question as they’re too damaging to the surface. Once the coffee mugs have been scrubbed, rinsing them underwater will remove all the previous remnants, and making them air dried finishes off the process. Proper care and maintenance mean that stoneware mugs will always be useful while looking their best.