I have seen things called chewies. They come as a necklace or bracelet. It would probably take some time and trial and error to find what he likes. Here are a few websites to check: https://autismcommunitystore.com/collections/se...
https://nationalautismresources.com/oral-motor/
https://www.especialneeds.com/shop/sensory-moto...

My son doesn't chew his shirt, but he does chew the inside of his cheek/lips and he recently started grinding his teeth repeatedly. He usually does this when he is super excited and sometimes when he is upset. From what I have read, it is a type of "stimming" behavior. I have seen the "chew toy" types of products online....beads, necklaces, etc. My son has no interest in those, unfortunately. I am still looking for an alternative....so just know, you are not alone. Trial and error like Ashley85 said.

Thank you

My daughter has been ripping her polo shirt tshirt for 7 years and we tried everything but nothing worked finally over her shirt we gave her a jeans jacket and trained her to wear it to her dayhab program also a thin material shirt worked polyester thin try these 2 things