My boy will poop on the potty pads, but prefer to pee outdoors. Our groomer has an indoor day boarding area and I noticed in addition to puppy pads, she had a 2 litre plastic soda bottle wrapped with a puppy pad and placed over the larger puppy pad area. I didn't ask but I'm sure it was weighted with sand, or something. I intend to try that.
Carole, Giovanni & Manny