When I read this I had to laugh. I thought my daughter was the only child that ever went through that stage.
She sucked on the sleeves of her shirt, coat, sweater, etc..all the time. It got to the point that she started to develop cold sores near her mouth because the area was always damp from chewing. I took her to a dermetologist finally because it got that bad. He suggested at the time to put Aquaphor on her face in the cold seasons to try to prevent her from getting the sores. However..there was nothing I could do to keep her from chewing. I just had to always tell her to stop when I saw her. She is now going on 11 yrs old and has finally stopped sucking on the clothes, blankets and any other piece of clothing she could get in her mouth, but she constantly is putting things in her mouth to chew on..plastic store tags, buttons, toys, etc..When I catch her chewing I always ask what she is chewing on and she immediatly spits it out. It is very frustrating, I understand completely. I wish there was some advice I could give you but all I can really say is to wait it out and constantly remind the child to get the items out of his mouth.Good Luck!!