What does the cornmeal do to accuracy? Have you tried that load on paper targets? I've heard of using it as filler for revolver loads but not in a longrifle.
There was a MuzzleBlasts article a few years ago where cornmeal was suggested for barrels with accuracy issues; e.g. a barrel that may have some pitting that's compromising patch integrity, in turn ruining group size. I've tried cornmeal and don't see where it has ever done any harm with respect to group size/accuracy and in one rifle it did some noticeable good. The patches I've recovered have always looked pristine, not even slightly scorched, when fired over the meal. I think what's happening is the cornmeal is a moving firewall and gas seal, so there's no blow-by or damage to the patch. I've found I can use a thinner patch, which when hunting makes for easier reloading in the field while maintaining the accuracy I could get out of a thicker, harder to load patch. I reload from a 'quick-load' tube with powder in one compartment, cornmeal in the other, and then push the patched ball in with my thumb and seat with the rifle's wooden rod. The rifle's a fairly short barreled .62, and I hunt in pretty thick woods. I've paper tested it to 100 yards, which is about twice as far as I'm likely to get a shot at a deer.
In a revolver, corn meal serves a different purpose. You might get best accuracy with a 18 grain charge, but the chamber might have room for 37 grains, and the loading lever won't reach to firmly seat the ball atop the powder. Then, the cornmeal is an inert filler allowing the ball to be firmly seated atop the reduced powder charge, and still be just under the face of the cylinder.
Corn meal is obviously an extra step in loading, and there's no reason to try it in a rifle if one is satisfied with the group size or as in Redheart's case if one wants to keep his powder away from any lube seepage. (And, for a squirrel rifle that might be fired a dozen times a day, a felt wad would be a lot handier than cornmeal if you can find or make wads of the right diameter.)