I do a little mixing and adding with the three mediums, only because i didn't know which would work best. These are some great ideas you guys are putting out.
There's really no point in mixing walnut with corncobb. Here's why. Walnut is courser. Courser cleans better and cuts faster, which is good for really tarnished brass. Not unlike course sandpaper, the brass finish is ok, but not particularly glossy. The scratches made are too rough for that.
Corncobb, is like very smooth sandpaper. Like the sandpaper it'll clean the tarnish off pretty good, but it takes longer. Since its smoother, a smooth shiny finish is the result....unless you add walnut. With walnut added the finish won't be any smoother or shinier than Walnut by itself can make, because the walnut is harder and scratches deeper.
Corncobb, being softer, scratches shallower, as does really fine sanpaper, but it won't cut fast, unless you add some polishing compound to it, like Dillon polish, Flitz, or Blue Magic. By the same token, the finer the polishing compound the shinier the finish....Meguirs Swirl Remover is about a fine as polish gets. It will cut slower but polishes brighter.
A decent plan would be to tumble a few hours with walnut if you have really tarnished brass, then polish it up with the corncobb spiked with polishing compound. If the brass isn't so bad skip the walnut and just clean and polish with spiked corn cobb. Keep in mind that so far we have only talked about initial cleaning and polishing. Then you size (and deprime if you haven't already done that with a universal depriming die).
Following that size/deprime operation, just plain unspiked corncobb is best to remove lube from your resized brass. 30 to 45 minutes does it for me, and with 20/40 grit corncobb, no flash holes get clogged.
....Just glittery plastic, imitation stuff tho.
Lots of automotive trim "chrome" is just plated plastic, lots of kids toys and electonic stuff too, etc. I don't need that look on my ammo.
Ranger can make all the tarnished reloads he wants, but I much prefer a professional looking product. And what are we "imitating"....nothing! Polished brass, sir, is the real thing! Do I do it 95% to impress at the range? No, that is just the result as I try to impress me. If my ammo looks better...I feel better. If I feel better I shoot better. It's too bad, we can't indulge ourselves, without always having somebody...attempt to rain on the parade.