Here are a few more tips that might help from my page on Chewing:

Do these things first to stop the chewing:

1. Pretend you are your dog by getting down on your knees and looking around your house. What do you see? Are there things on the floor that would be interesting and fun if you were a dog? How about shoes, pencils, paper clips, clothing, slippers, etc.?
WHAT YOU SHOULD DO: Pick up all objects from the floor and put them where they belong, or put them in a closet and shut the door.

2. Look around your house. Do you see a door that is open? What is on the other side of that door? Is it a closet with lots of cool things on the floor? Or is it a bedroom with sweet-smelling socks that are easy to reach?
WHAT YOU SHOULD DO: Close all doors that lead to trouble. The best thing to do is close all doors except for the room you are in. If your dog is having behavior problems, he should be supervised at all times.

THERE IS ONE MORE VERY IMPORTANT THING TO DO!

3. Look at the furniture in your house. Do you have furniture that is appealing to a chew-happy dog? Most furniture is. Are the legs made out of tasty wood? Does the sofa have an inviting, tempting upholstery (the cloth or leather that covers your couch)?

WHAT YOU SHOULD DO: Decide with all of your family that you will not leave your puppy alone in the house until he is grown up (maybe as old asa 2 years) and knows his manners. You will not leave him alone even for an hour. If you leave the house, you will put your dog into a crate, a pen, a bathroom or utility room, or leave him outside.

Give your dog things to play with and lots of acceptable things to chew on. Puppies really like interactive toys like Kongs, and food cubes as well. Don't forget to give your pup lots of exercise, too. Good luck, it will take lots of patience, but it will end eventually.