Velcro straps can be a bit of a mess, but there are a few ways to clean them. The first way is to use a mild soap and water. Soak the straps in the soap for about 10 minutes, then rinse them off. The second way is to use a vacuum cleaner with the hose attachment. Put the strap in the vacuum cleaner and turn it on. The strap will start to spin around and will eventually come out clean.