Good product with limitations - Lyman Ultrasonic Case Cleaner for Brass Reloading

Does a good job cleaning brass cases - pistol and rifle. I use the ultrasonic case cleaner after tumbling, sizing/decapping and pocket cleaning/uniforming my brass cases. It does a decent job cleaning the inside and pockets of the cases, but leaves the cases dull in color. I then retumble them with corncob/polish to bring them back to reasonable shine.