I just remembered I saw on some dog show that they installed a dog gate around the front door so their dog couldn't escape. It might be helpful, especially if he's having trouble with door knocking too. I kinda wish I had one. It looked kind of like this one.
High Priestess JessMess, follower of the Goddess of the Coiling Way and Confiscator of Concoctions in the Order of the Curly Crusaders