My son did that chewed holes through his shirts. I got him a chew toy, I know it sounds bad but I found some that were shaped like fun animals. It took him a few days to realize chew this instead but it worked and he eventually stopped.

You can try chew necklaces and things like that but to be honest they have mixed results. When my daughter was doing it we got her cloths with short sleeves and low collars to help but she still did it to some extent. She moved on to another stun and dies not do it anymore. You can also try to redirect but that is not perfect either. Sometimes they just have to work through it and there is no real timetable.

My son who is also five used to chew on his shirts too. I used to give him a food item to chew on instead with a texture that I thought would be satisfying. I used the cliff kids fruit ropes. I'm not sure exactly when or why he just all of a sudden stopped.

Spray vinegar on the tops of his shirts...I did this and he stopped. But of course, These sensory issues manifest into other problems. He now has to sit on his clothes when sitting in a chair(ugh).

My son chewed holes in his shirts everyday when he was 5 and 6. Everyday he his shirts were soaking wet. He also chewed everything else. We used to give him frozen teethers and chewlery but he'd only use them at home when others were not around. Our OT suggested dog toys because they were stronger but he didn't like that idea! He did eventually stop and move on to other stims to calm his anxiety, like spinning his wrists, etc.