Use detergent for leather!!! There's stuff you can get from Dover or possibly your local tack shop called Pepede (pronounced PEE-PEE-DEE) that's detergent just for sheepskin, breeches with leather, etc. It comes in a small orange bottle for about $15. I wash my halfpad on cold, delicate, with a capful of the stuff and it comes out fluffy and clean! (and DO NOT DRY!) Mattes also recommends stuff called Melp but I haven't tried it yet.