I've never seen the sprays work, especially with a lab.

Here's the best solution I've given people. Crate and kennel.
When you can't supervise your dog put it in a crate or a kennel. That way it can't chew the bedding or anything else you don't want.

If your dog doesn't like the crate and kennel, tough luck. Feed it in there a few times and it will start to like it as a positive association will have been made.

If you put the dog in there and it whines and sounds like it's about do die....ignore until quiet and then slowly approach the crate and let it out on your terms.

The exercise suggestion is a good one as well.

Also, I'm guessing the dog has not been fully trained on basic obedience, that would help too.

Best of luck.

Kg