I'll tell you guys I been vibrating brass and tumbling in bulk for years, any polishing compound like brasso, flitz, car polish, even sand blast sand etc when added every half dozen uses will work fine. But if you want perfect, absolutely clean, inside and out, the only way to go is the water method and pins. It is unreal how clean they are. But I agree, they don't shoot any different but some guys are sticklers about what they look like and I'll admit I've gone to matches with rounds loaded that morning and never polished that look like hell and still shoot. It's a personal thing I guess. But you want bright and shiny! Water tumbler!