Do not isolate your dog as punishment for chewing. This will create more tension and lead to more chewing. Do not physically punish him for chewing. He is chewing to relieve tension, and punishment creates more tension, hence, more chewing. Instead, give him plenty of exercise before leaving him home alone.
Exercise works the same way for dogs as it does for humans.
It relieves tension. If your dog insists on chewing, there are some things you can do to slow down the habit and redirect the chewing to permissible objects. Do not put any personal belongings in this box such as old slippers, knotted socks, or any leather or fabric items. This will teach him that he can chew but only if the item comes out of his toy box. If he has a personal item in his mouth, do not pull it out.