Andy is chewing holes in his shirts

Andy loves to chew on bibs and his shirts. He is really starting to ruin his shirts by grabbing the collar and chewing on it for as long as he can. He usually requires several shirt changes at school due to soaking his shirts from chewing and drooling. He is tearing up and ruining his bibs and we have to throw them out, because they are disintegrated. He is now ruining shirts at a fast rate. They are getting so filled with holes that we can't have him wear them again. I already have to cut buttons and zippers off of all shirts before he wears them. Otherwise, he will chew the button off and crack it right in half with his teeth. The buttons and zippers also present a choking hazard for him.

I'm having to buy him all new shirts, and looking for stuff on sale and new with the tags at resale shops for cheaper. I also started letting him chew on the baby's receiving blankets, since she has so many. He enjoys holding them and chewing on them, but eventually throws them to the side and forgets they are there. He will then go straight for the collar of his shirt. Sometimes, we are removing his shirt until bed time, when he won't stop chewing on them. We then put his shirt on after he has fallen asleep.

The most frustrating thing of all is that Andy WILL NOT pick up food and put it in his mouth. EVER. Even after years of trying to get him to do it. He just will not. He will put other objects in his mouth though, like blankets and clothing with absolutely no problem. If it is food though, he will not do it. He will pick it up and throw it on the floor, or make a mess with it, but won't pick it up and bring it to his mouth. It's very frustrating.