I guess that largely depends on how much you use it. I've used a bowl of corn cob for over a year.....but I recharged it occassionally with Midway's polish. I also throw in cut squares (about 2") of used clothes dryer sheets with every load.................those pull out a LOT of dirt from the media.
And throwing in a few ounces of mineral spirits every few months helps to keep it working well too.
It also depends on what you are cleaning. How dirty the brass is to start with. Volume of brass your cleaning. And just how "polished you want your brass. generally speaking it does last quite a while. I discard mine when I feel like it just isn't working well any more. If it takes more than a couple of hours to clean an average load then its probably time to replace it. KN
I use a product called Lyman Tuf-Nut. It comes in walnut and corn cob as well and contains jewellers rouge. The entire tumbling operation is dry so your media is not apt to become contaminated nearly as fast. Also the media will come out of your cases easily when finished because it is dry.
I find it lasts quite a long while. Best wishes.
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