To train your dog to stop chewing on a specific object, coat the object with a dab of BENGAY. The smell will repel him.
Try: Heinz White Vinegar and Heinz Apple Cider Vinegar.
Mix 5 ounces of Heinz White Vinegar, 5 ounces of Heinz Apple Cider Vinegar, and 5 ounces of water in a 16-ounce trigger-spray bottle. Shake well. Spray the solution on whatever furniture your dog likes to chew.