Well, I gave it a go - and the result: I will *never* stir-fry in the kitchen again! It's a revelation to use a really really really hot wok!
I don't think could make it
*too* hot. I used about 2/3 of a chimney starter full of charcoal, and dumped the hot coals into as compact a pile as I could, and rested the wok on the grill surface. Non-stop serious sizzle from the time I put the first ingredient in. They're not kidding when they say you can cook a dish in 1-2 minutes this way!
HINT: Pile the coals near the edge of the grill, not the center, and the grill will shield you from the intense heat.
I don't think a gas cooktop or a gas grill could get anywhere near hot enough. So, give it a try if you like real Chinese stir-fry!
I found that my family doesn't care much for Szechuan peppercorns, though. They're a trifle too exotic.