Brown Bag Cookie Molds are made of a special, fine clay that produces a durable, ceramic mold.  Although the molds are supposed to be non-porous, you should avoid cleaning them with soap if you find that your mold has a stain or discoloration.

All you have to do to clean them is prepare a paste of 1 part baking soda to 3 parts water (for example: 1 T baking soda to 3 T water).  Dampen your mold and place the paste over the stain.  Allow the paste to remain on the mold for 15 - 20 minutes, and then scrub with a nylon pad or toothbrush.  Rinse thoroughly and air dry.

This method works great on any stoneware cookie molds and baking dishes.  Your mold will come out looking like new!