I wouldn't do that. The walnut hulls aren't overly abrasive and will do a good job of removing tarnish and lightly cleaning the metal, but not much else. If you moved up to something more abrasive like ceramic media it will do more, but that is where you will round over edges and take out all your detail. Really there is no shortcut that works well. Your best approach is using files to clean up/refine the surface, followed by wet and dry sandpaper backed with your file in increasingly finer grits. Tumblers and buffing wheels are a quick way of ruining your work.