T.C.
My son has ADHD among other issues, and he does things like chew his shirt collar, make sounds like sucking a lollipop, pick his nose and then put his fingers in his mouth, wipe his hands on his shirt instead of a napkin, poke holes in his shirt with a pencil, etc.
In kindergarten, he would get in trouble for spitting and they made him spit into a trash can for 5 minutes. Now in 2nd grade, he has again gotten in trouble for "spitting" (this time sticking out his tongue and making a pbfht sound). The new school's answer is to send him to the office for days at a time, writing long apology letters for spreading germs. I don't think anything helps except him just moving on to a new behavior after a few days.
The school does provide him with a springy plastic necklace to chew on, and sometimes they can get him to substitute that for the other undesirable behaviors. I've seen the necklaces in OT catalogues.