I was just thinking about this yesterday! I have noticed that the quilt we use every day on our bed (given to us 4 years ago when we got married) is dirty at the top. I think it has nothing to do with whiskers, though, it's oil from our fingers when we pull the quilt up at night. I was thinking about how it could be done to protect the top of the quilt. Even after I wash it I notice the top is still darker than the rest of the quilt.
So glad this came up! I may have to try making one of these.