Use vicks vapor rub and socks. Even the worst cough can be stopped within 5-15 minutes, and lasts hours. Just apply the vapor rub generously to the bottom of your (or child's) feet, and cover with socks. works 100% of the time, and has been proven to work better than prescription drugs! This REALLY Works!
If students were upset, I would let them go to the "safe place" and this could be the timer there. They would need to shake out all their anger on the bottle when they got there, and then watch and wait until the glitter settled before returning to class.