Adam Greenfield has posted his review of a 1994 Tchkung show. I saw them a few months ago, 8 years after this review was written, and it still holds true.
What did I want them to do with that energy? What might I have done with it myself? Alternately, what might I have done if only it was asked of me in that interval before the showbuzz wore off? Part of the problem here is that Tchkung is playing with fire, in more ways than the merely literal. The piercing, the firebreathing, the dervish-dancing, the relentless rhythms: these are all shamanic techniques for the alteration of consciousness, and there is no doubt but that they work. In their original contexts, they are all used by people undertaking specific initiatory journeys, when guided by others steeped in the traditions of their use. Of course, none of these conditions obtains at a Tchkung show. What happens when you put several hundred people into a suggestible state, in an environment filled with extraordinarily powerful signs of no fixed meaning?