They clean their paws when they are dirty, just like cats. They dig little chunks of dirt out and leave them all over my couch. (Thanks a lot PEPPER, I love you too!) This is why smart dog owners train their dogs to stay off the couch when they are puppies.
For revenge, I take lots of pictures of Pepper and her clean, clean paws. She hates having her picture taken. She even gives me dirty looks when I take too many pictures.