Contrary to what most dog owners believe, dogs are not capable of feeling guilt. When you come home after a long day at work and find that your doggy pal has chewed a hole in the couch, eaten your favorite pair of shoes, or has redecorated your bathroom, you begin to question your consent to dog ownership. Your first reaction is: "O MY GOD!!" Then, "Where's the dog!" In slinks Rusty, all twenty pounds of downright shame and guilt, right? Wrong! Well, you might say, look at him- he's groveling on the floor looking real worried; in fact he's completely rolled over on his back. I know he's sorry!
The truth is that dogs have lousy short-term memory, and unless you catch him in the act of rearranging your belongings, chances are he won't remember what he did when you finally find his mess hours later. The behavior that you see after you've discovered his crime is submission, not guilt. If you placed a little mirror above your dog's fuzzy brow and saw the way you looked when you found the mess, you'd lie down too, just to play it safe. He's no dummy: he knows that if he submits chances are that he'll be spared your wrath. This would explain why you can yell at your dog for 10 minutes about how bad he is for chewing the couch or your shoes, and he will stare at you blankly and return to his destruction the moment you are out of sight.
If destructive chewing is a problem for you the best solution is to not allow your dog so much freedom. Use a crate or gate him off in a dog-proof room when you're away, and provide him with his own toys to chew. Make sure that he's walked and fed on a regular schedule and gets plenty of exercise. Gradually increase the amount of freedom he has and be sure to watch him closely as you do this. If he gets into mischief back up and start again. The dog must earn his freedom gradually or he will chew out of anxiety. Most destructive chewers are either bored or anxious and chew to relieve their tension. Confining a dog to one area with plenty of his own toys to chew saves a lot of expense and helps prevent high blood pressure in humans.