I understand your frustration, but that's what they do. Obviously the muzzle works, but only while its on. The command "no" works well and giving them something they are allowed to chew. If your worried about stuff when you're not looking, then a cage is the answer. I've never used sprays etc.
What I don't understand is you are out in the woods where you are away from household valuables, let it have a chew, its good for them. Your pup is 11 months old let it have a chew.
Yes I've had a few and now I have two. You should see the state of my chew proof kennels ? . They don't chew