Eileen,
My favorite way to deal with stealing items or even chewed items is similar. If the item is stolen and my dog is in the process of running off with it. I call him to me, greet him cheerily, and say "Thank You, Bailey!" No matter how mad I am, I always make him thrilled to approach me, rather than run the other way. If I can, when he comes to me, I trade the item for something he CAN chew. It's making a great deal, and my dog is always happy.
If he has already chewed the item, I truly regard it as my fault and just chalk it up to a lesson learned. You said that you realize the objects should not be available, so you're aware of the error. I train my dogs with a 100% positive approach. Destroying something is always something that I neglected to take care of in the environment. I can't promote some type of punishment because I don't use it. But my little thief is always happy to have another happy activity to choose from. Good luck, and I hope this helped.