After monitoring this thread and giving it a lot of thought, I guess I would change my "vote". While I still think it's a slippery slope to take actions into one's own hands (like those at Quartzite did years ago), I would be in favor of a governing body of some sort taking action on this to minimize the likelihood of further deaths. By that, I mean if the ARHA, State Parks or someone like that would take action to alter this hazard in some way, then I think that would be the best solution. At least one would hope that those kinds of governing bodies would be able to take things on a case by case basis and avoid the "slippery slope" that many fear. Besides, they could use funds that they use for other improvements to do it "right". I am not sure what "right" is necessarilly, but hopefully they would. Dynamite may leave sharp edges and such, just throwing rocks in migh not stick, etc. They would have more resources than individuals would to make a permanent, minimal impact change to the rapid/river.
Flaco, thanks for the video. That's one of the best images I've seen of it, because I stay away from that section at low water myself, just because of this possibility.