I tumble to get sand and grit off (a lot of that here in FL), but pre-tumbler days it was wipe with a soft cloth. My brass only get "shiny" when I forget the tumbler's running for hours. Then ,a couple of weeks later, it's tarnished again regardless.

How you clean and what device you use is all relevant to how clean and shiny you want your brass to be, and how much effort you wish to expend doing so. Each method has its own merits and disadvantages. Choose what suits you best.

For range work with a .38, I'd use wadcutters, but any other lead bullets available would be considered.