I took a workshop (a while ago now) at Jazz Camp taught by Kid Beyond. He was using an echoplex and a mic. The class format was fairly simple: he started with a demonstration and talked about how he uses loops in his own work. That was impressive in itself. Then he had as many people as time would allow try it for themselves.
I demonstrated a looping pedalboard at Outsound's Touch the Gear event this year. The cutest thing was that almost all of the boys would approach me two by two, I guess to seem like they weren't flirting too much! Each conversation was different: one guy had never seen the gear in person (he had hip hop mc aspirations) so we were playing with how to time the start and end of loops, other people wanted to see what I could improvise ( http://soundcloud.com/reklawysdnil/kfjc-logo was made on the spot), while others made their own wall of sound.
My recommendation is to start with a splash by doing a practical demo for entertainment value and then launch the dry stuff.