When I did a demo at David's English School I did the demo for staff members. When I was studying in my education classes in college we often used classmates to play the role of students. It doesn't show much about how you control a class, though. So there are limitations to this approach if the school you are demoing for focuses on young children.
I guess another option is to make a demo video. If you are still teaching you could get permission from your boss. Or, you could invite some local kids over and give them a free 20 minute lesson so that you could tape it yourself.
You could then burn a VCD and use that as part of your application.










