Giving puppies appropriate things to chew will reduce the swallowing of scraps left over from the chewing process. A dog who consistently swallows non-food objects does so because it makes him feel better, at least temporarily. He may be swallowing these objects because he is hungry or is experiencing a diet deficiency. Both of these can be remedied by feeding him a proper amount or by changing to a quality food with a balanced nutritional recipe. Sometimes a dog will chew to relieve stress and swallow some of the scraps in the chewing process.
Stress is built up from boredom, lack of exercise, physical restriction, or physical punishment.
If your dog is chewing and swallowing something he shouldn't, you can bait a trap by smearing a distasteful substance on the object. There are a number of commercial products which work or you can use something as simple as Tabasco sauce. This remedy, however, is really only treating the symptom. It is best to understand the motivation for his behavior. Your dog may be eating non-food objects because he is unhappy with your relationship.