The question I have for you is why are the dogs left alone and unsupervised throughout the day? You know for a fact that the dogs are chewing and ingesting things they shouldn't, so you should be suervising them at all times. Swallowing a chunk of something can lead to serious problems with blockage in the throat or intestines. You're looking at potentially paying a lot of money for surgery or even coming outside to find a dead puppy. I suggest you bring them inside where you can watch them and play with them, and control what they chew, and then put them in a kennel when you can't watch them. They can go back to being porch dogs, if you insist on that, after they've grown out of the chewing and had some training.