They have indoor artificial turf pads for this sort of thing now. There is a plastic tray on the bottom that you clean off regularly so there is no odor. This is a great longer term solution to save money as it is much cheaper to maintain than replacing disposable potty pads at the store every week. It also is more environmentally friendly with less trash going out the door. Just clean and reuse the turf. Amazon has a wide variety for various prices depending on size and durability.