How to Restore Shearling Slippers to Their Original Fluffy Glory
Make a diluted cleaning solution for the lining. In a small bowl, mix together about one part wool-safe detergent (like Eucalan Delicate Wash or Dirty Labs Hand Wash & Delicates Detergent) to about four parts filtered water, or follow the detergent manufacturer’s instructions. It’s important not to use too much detergent; otherwise the slippers won’t get fully rinsed, just blotted dry.

Dip your clean brush into the solution and, working in sections, apply small amounts of it into the woolly lining. Use short, straight motions to apply a little of the solution at a time, taking care not to oversaturate the wool, and blotting dirt away with a cloth or paper towel as you go. A small cleaning brush or toothbrush is helpful again to get into nooks and crannies like the toe box.

After you’ve finished cleaning the lining, dampen another clean rag or paper towel with a little water and blot the liner to remove the cleaning solution. Then, with a dry rag or paper towel this time, blot the inside as dry as you can.
Now let the shearling inner dry. Open the slippers up as much as possible to increase airflow, and allow the lining to dry completely. Placing the slippers somewhere warm, such as in a sunny spot or near a heat vent, will help expedite the process.
Once they’re dry, use a clean, dry brush to fluff the shearling lining. If any matted or still-dirty bits remain, you can carefully trim them with a pair of scissors to prevent further clumping.