I'd say its like taking a tack hammer and giving the resonator a solid tap, about that loud. I did find out the '99s trans went out some years later, but still ran just fine like that.

It can't be good for the engine. I can see it being hardest on the valves. So.. maybe "moderation" in applying full, then cutting the throttle?

It's kinda hard for me to picture what's exactly going on during this type of misfire.