Now you have a bad habit that is sometimes hard to break. The best way to prevent inappropriate chewing is to exercise your Maltese, supervise him when he is out and about and confine him to a kennel or crate when you are not watching him. Puppy-proofing your house is also advised. Your Maltese needs a variety of chew toys. You should have 16 to 20 toys.
Half are out one week and the other half are put away.
Rotate the group each week. In this way, your dog will not become bored and find new toys that are yours. I provide a toy box for my Maltese. They take toys out when they want to chew. I don't expect them to put them back though.