I have used treated walnut and corncob. Treated walnut is usually a red color and gets all over everything and leaves a fine powder everwhere. It will get just about anything off your cases and leaves them a with a satin type finish. Corncob is not ass aggressive, or messy, and will leave the brass looking like brand new (high polish). I no longer use the walnut at all and only use corncob. It might take a bit longer to clean the cases, and yes you have to dig the corncob out of the primer pockets, but it is alot cleaner than the walnut. I am talking about both media being treated. I have never used untreated walnut, it might not be as messy, but as far as treated walnut I will never go back to it.

I got some untreated corncob from a pet store. I didn't clean much as is, what can I treat it with? Doesn't Brossa have ammonia? Is there something else readily available to add?

I use the treated Walnut followed up with untreated Corn Cobs. Works great for me.

Rick

My local feed store sells me 1/8"-grind corncob for $13.00 per 40-pound bag. It works fine even for rifle brass, but DO NOT get the 1/4"-grind stuff because it certainly will be tough to get out of bottlenecked cases, just as someone here has already warned.

I use Turtle Wax "Scratch and Swirl Remover", with a couple ounces added to each load of corncob and brass in my Midway tumbler. It polishes a bit more aggressively than regular Turtle Wax, but nothing severe. The Turtle Wax products leave a thin wax coating which tends to keep the brass bright for long periods of storage before loading.

My most extreme job using this material to date was some 'donated' commercial .30 US Carbine brass which was DARK BROWN with tarnish, having no brass coloration showing at all. I let the tumbler run for 18 hours, and the result was cases that looked like they were fresh from a factory box.....brilliant, shiny, highly-polished cases!

For the cost of my cheapo corncob grit, I don't worry much about how long it lasts, but I do usually get at least several polishing runs with each load of corncob. I also don't worry about how long it takes. An hour or two will get cases clean, but my tumbler often runs all night long too. After forty years of handloading, I do like my ammunition to LOOK professional, and to me that means clean and shiny.

I buy untreated walnut shells and add a small amount of Brasso or whatever media I have on hand..Its not messy and works very well with nice shiney cases...

My two cents
I use sawdust with polishing paste in a rotary tumbler. (Paste bar used by bronze polishers). It maintains cases clean and shiny. Too light for tarnished cases.
Cheap rice works fine in vibratory tumblers.

Although I have not tried rice, I have a friend who used it in his tumbler for 15 years....swears by it....My guess you will get a clean case, not a highly polished case....Me, I look for clean

I know I am in good company and doing it right when I do like Ray Atkinson does it.

I put it in the tumbler before i go to bed and empty it out next morning or next evening. Some times leave it on for several days or so. Then it is definitely shiny, very shiny.

Impresses everyone with that and using Ballistic Tips.
Looks pretty says my wife. ( Women!???)

Cheers and Good shooting
seafire