Leather can be treated many different ways, and different stains require different treatments. Some stains require a little more time for preparation and cleaning--see the Resources section below for more tips on how to remove specific stains. Most leather stains can be cleaned with soap and water. If you are careful, there is no need to spend a lot of money on expensive leather cleaners or stain removers.
Brush off any dirt that hasn't set into the leather. This will help prepare the slippers for stain removal.
Take a clean, damp washcloth and place a small, pen-sized dot of gentle-use soap on the cloth. Gentle-use soap will not stain the leather.
Rub a cloth lightly on the leather, working the soap into a lather.
Wipe the soap off the shoe.
Rub a dry towel across the leather.
Apply leather conditioner. The leather conditioner will help prevent future staining.