With revolver and rifle brass, it never gets too dirty. So I vibrate them in corn cob.
The pistol brass gets really bad. Rocks, mud, etc. I will not run that through my dies. I should say that I am real cheap. I considered the wet tumbler with pins, but it costs a lot. I have a rotary separator I use to separate the corn cob from the brass. When I bring in the nasty pistol brass, I put it in the separator, and fill the tub with water, citric acid, and car wash soap. I tumble the basket by hand for a while. No pins, and the brass has not been de-primed. The agitation of the cases gets them clean on the outside, and gets all of the mud and dirt out. The inside does not get new-sparkly clean, but the outside looks as good as with the pins.
And it is cheap!