I load about 3,000 rounds a month of mainly pistol ammo, 9mm, .40 and .45. I've got two kids in college, so doing good to shoot, and haven't got around to getting a tumbler, and would need a BIG one and it would run a LOT, so came up with a different method.
When I get a couple thousand of a caliber I dump them in a small bucket, add quite a bit of Simple Green and hot water and let it sit a couple of hours. Dump that water, add clean water, and add a few squirts of Lime-Away. Let that sit for about 10 minutes, drain a couple of times, and the cases come out clean and shiny, looking like new, inside and out. I dump them on cookie sheets and pop them in the oven at 150 degrees for an hour or so.
A tumbler might get them slightly shinier, but these work great for me, and allows me to process fairly large quantities with little work.