I agree with some crate training and allowing him to sleep in a crate in your room at night. Some appropriate chew toys would also help. Dogs chew as a way to relieve stress and boredom, giving them appropriate things to chew on helps them to relax and unwind.

To muzzle them and not let them chew anything would not only be unsafe, but cruel to a dogs mental well being, imho.

I have muzzled Oliver to stop him chewing... but only when I had to take him in the truck with me and leave him in it for a time.... after Oliver ate my seatbelts, console and started on the steering wheel (I live out of town, and when I go into town, I had to bring the dogs, I did not want them shut up and alone all day.) BUT I HATED doing it, and worried constantly about him. I used a basket muzzle though so he could open his mouth and such. I finally got a cap for the back of my truck (darn expensive dogs! $1000) and put him in the back when I had to leave him... solved the problem.

If I were you, I'd avoid the muzzle and follow others advice... Muzzling in that situation is really not fair.

Not read the whole thread but it appears from your post that you are not keen on crates or muzzles, so in terms of environmental management what other choices are there?

Dogs can chew their way through walls, so you might consider the following:

Up the exercise both mental and physical a tired dog is a happy dog and less likely to chew.
Provide a suitable chewing item eg raw bone, nylabone etc.

Muzzling ANY dog without SUPERVISION is a H & S risk as the dog could vomit and suffocate etc etc.

Dogs should NEVER be muzzled without supervision.

Agree with others - putting a muzzle on an unaccompanied dog is tantamount to cruelty in my opinion. You say the dog has company during the day and is fine so I am not surprised she is chewing when she is put into a small room on her own. I think I would do the same

You had her in the bedroom when she hurt her paw and she was fine so why on earth can't she sleep in there all the time on her bed? I know you would have her in there like a shot so it is a matter of persuading the OH.

Good luck.