<font face="Comic Sans MS"><font color=#006400> I never heard of chewing on clothes... paper, yes, clothes? wow
When I was younger, I got into the habit of sucking on the end of my braids (gross, I know

). Nothing my parents did worked to get me to stop. Once, when we were in a local store (Whitefront - I'll never forget it), my dad got a pacifier and gave it to me, and told me that since I had this great need for sucking that he was going to give me that pacifier and I was going to have to wear it on a rope around my neck, and that he was going to write the teacher & let her know that I was not to take that off.

I had to carry that stupid pacifier all around the store, and I begged my dad not to get it for me, and I promised that I would stop sucking on my hair.... Well, finally, he relented, but he told me if he ever caught me sucking on my hair we would get that pacifier and I would have to wear it around my neck.
You know - I
never sucked on my hair again.
Was this cruel? Well, I never got mad at him. I was just so darned relieved that I would never have to wear that thing.
I still knew that my dad loved me and I never sucked on my hair again. So, this worked for me.
Maybe you can think of something that would really encourage your son to stop chewing on clothing.