You’re dog could be chewing up your stuff for several reasons based on their age and the circumstances. The main causes of chewing are teething, boredom, and stress.
That would usually be an example of stress chewing, because you’re not there, but it could also be linked to boredom. First we would have to determine whether or not your dog is getting stressed out by you leaving. If they are comfortable with you leaving, then the answer would be that they are bored, and you haven’t taught them what is and is not acceptable to chew on.
Crate training is very important, and chewing is one of the main reasons for it. I always like to say it’s one of those training we won’t use forever, but one we are going to use for now.
I can help you teach your dog that their crate is a nice, safe place. So they won’t mind going in their while your away. I can help you teach them what are the appropriate items to chew on, and how to make chewing on those items their new habit. Lastly I would give you the game plan with structured steps to giving them more freedom to wander the house while you are away. It will take time and effort, but if you follow the plan you’ll be there before you know it.