Ive been doing this for years and have seen no ill effects. My brass doesnt look like factory but they seem clean and the insides seem clean as well. I put some dish soap into a five gallon bucket and fill with hot water. Stir, stir, stir and then I dry it on a dehydrator. Does anyone know if this can have any bad effects on my brass, rifle or dies? Or does anyone have any other brass cleaning methods without using a tumbler?