Create a pattern or habit. 20 minutes after you feed or water a pup they poop and pee. You can set your watch to it. Take him out after you feed or water him. Give lots of encouragement for a "job well done." Create training was very successful for us as well.
As far as the chewing goes, just rub some Gurkha's all over your stuff. He'll never touch it.
haha that with the combo of Apple Bitter were golden