You could teach the class coutners to headlocks
If the headlocker and headlockee are facing the same way and the headlock involves a hand going under the chin, the headlockee should anticipate when the headlck is going on, and when it's about to go on, they should grab the headlocking arm with both arms, and throw the headlocker over the side of theirr body. If it's too late, doing things like kicking the back of their knee or pinching their inner thigh will loosen their grip and then they can be thrown.

If they're facing opposite ways and the headlock involves the head going under the armpit, the headlockee should attempt to reach round the back of the headlocker's neck, grabbing them and falling over backwards. Hopefully, the headlocker should be thrown onto the ground and with luck, the headlockee will end up sitting on top of them.

Other types of headlock can be countered by stamping on the headlocker's feet or elbowing them in the stomach and then throwing them once they've loosened their grip.
( mistaspakkaman and the inedible shifting caterpillars, Mon 1 Jun 2009, 20:37, Reply)