Why don’t you try to Kancho back?
I’ve found that there are three ways to deal with Kancho. The first is to get all pissed off and offended by it. I don’t see the point – they’re just kids and to them there’s nothing wrong with it. And if I did that, it would create this whole “Oh my Gosh, we can’t play around with teacher or he might get angry” attitude which I don’t want. It’s not like this is going to cause any permanent damage or even discomfort. So I can be indifferent to it, even find the humor in it. But maybe it’s easy for me to say because I have my trusty Kancho Sense™ and I’m a pro at Dodgedick.
The second way is to respond in kind – counter-Kancho, or hit them with one of America’s specialty attacks. But I’ve found that if you do that, it basically tells the kids it’s game-on, and they’ll step up their attacks. No one wants to lose to teacher, after all.
The third way, the method I employ, is to put the fear of GOD into them. I threaten to do stuff, but don’t actually do it. That way, their imaginations will take over and make the repercussions out to be worse than they actually would be. “Hmm, I can Kancho teacher, but what if he Kancho’s me so hard that it would make Tom Cruise The Second to Last Samurai? I’d better not risk it.” Been working well for me so far.