Good story and lesson! Where I live we call it subbing. I am a sub for a vocational school but high school students come there to get initiated into "Medical Fields". That's the class I sub for. These students chose to take this course so they behaved well. I interacted with them very little as they did the assignment the teacher left for them. If they call me to sub at a local school I will be initiated into that world you describe and I am not sure I can handle it. Time will tell. Do you still sub at all?