Discuss chemical weapons. Show water bottle with spout, gas mask, shatterproof visor, shatterproof goggles, swim goggles, and respirator. I want a lawyer. Practice with Magic Words flash cards. Teach the Magic Words chant.
Police interrogate every participant, each of whom has to say the magic words.
You're not a suspect, we're simply investigating here. Just help us understand what happened, and then you can go. It's my job to decide whether to give you a citation and let you go home, or keep you in custody. If you don't answer my questions, I won't have any choice but to take you to jail. Your friends have all cooperated, and we let them go home.