I always thought this was a gimmick but decided to give it a try especially since our 16 year old Irish Wolfhound mix sheds a lot. We also have a Border Collie mix with a thick second coat. The amount of hair vacuumed on the first tries were amazing and I also used the deshedder in the BC mix later on. She is scared of vacuums but relaxed and even took a nap while I groomed her. Worth every penny. No mess at all