Don't know if this helps anyone, but this is what I was told to do with my ballet slippers. 1. Disolve a little cleaning detergent in hot water, then add cold water until the water in the bucket/sink is lukewarm. 2. Soak your ballet slippers for 30-40 minutes, then rinse soapy water off ballet shoes. 3. Use Sunlight Soap or Wonder Soap (usually a dark yellow block of soap) and gently rub over the areas where dirt hasn't been removed, then gently scrub with an old tooth-brush, or a clean soft-bristled polish brush. You do need to be VERY careful when scrubbing canvas shoes, as they have a tendency to rip or fall apart if they are a bit old or are quite worn out. You also want to be careful about the amount of soap detergent you us. 1-2 Tbsp should be enough!