We have a 12 week old pup who we are potty training. Currently using the bell method. I think having a dog door would make things so much easier. However I don’t have a sliding door. We have French doors. My options are to install one in the wall or put two dog doors. One that goes into the garage and one then the one that goes to the yard. We live behind a canal and field and people are always walking behind canal. The door on wall would have to go on the side so not visible and the garage door is already on the other side of house.