Megan,
As Andrea points out, adapting the WBT teach okay works in many areas. Clap Clap Read!, OK!, clap clap Work (Compute), OK! (for doing a math problem). Draw; Debate; Practice...
I think it is worth noting that not only do your little ones have trouble with the idea of waiting until after they have clapped to say OK (work quiet), when I am working with adult teachers they have the same issue. It always gets a lot of giggles when they mess it up - a point I am delighted with as I point out how much fun they are having in WBT training. Then I connect it to their students pointing out the students will also have fun with it.