Well folks, let me shed a little light on this deep, dark subject.

In my opinion when you hit the typical silty sand bottom where blackmouth are feeding with your booger ball you are basically stirring up a cloud of silt. Fish can see and hear ok, but what they really can do is smell - so well that if you stick your hand breifly in a fish ladder, all the fish will instantly stop running up it for 5 minutes. Anyway, this cloud of silt attracts fish by scent, and simulates what a blackmouth does when he grubs in the sand for sandlance or shrimp. Blackmouth that have been doing this are all scarred up around the mouth from getting scraped by the occasional shell when grubbing in the sand. So hit the bottom a few times, stink up the area, and look out!