All leads can be washed, but how easy it is to wash and care for varies by material. Biothane is a slick, smooth plastic that is very strong and resists tearing. It won’t absorb water so if it gets wet or dirty, you can just wipe it clean and dry it with a rag or towel. Nylon is easy to wash and clean but will take a little time to dry because it will absorb water. For rope and leather, wash by hand using a mild soap. If your dog has allergies, you might want to use the shampoo that you use when you bathe them to wash your lead. You can wash nylon and rope leads in your washing machine by putting them in a garment bag with a couple of towels to pad them so the metal hardware doesn’t damage your machine.