It is always a struggle with an adult dog that is not house-trained to get him fully compliant. Be strict with your potty training and never leave him unattended, keep him on a leash in the house so you can take him out when he starts to sniff to raise his leg. For the times you can't be present, crate train him. In addition, try spreading his scent over the home by rubbing his face with a facecloth to gather his scent, then rub the cloth on door frames and strategic pieces of furniture. Then amplify these reassuring smells by spritzing it with DAP.