I do believe this kind of thing can cause feeding by tricking the fish to thinking a insect hatch is occurring in the area. Take a brown paper bag fill with rice and put a rock inside to sink it. Tie a fishing line to it and lower into the brush pile. Give the line a quick jerk to bust the bag open, disperse the rice. The rice will swell up and rise to the service causing a simulated insect hatch and hopefully a crappie feeding.

Or carpet bomb an area with rice it will sink and rise and I have no doubt crappie, bream and catfish will feed on the rice thinking they are insects. Rice is a awesome cumming tactic. It sinks and rises giving you a two fold cumming attack and fish like it better than kitty litter. Just Taste better. HAHA!!!