IF tumbling cases was "necessary" we couldn't have reloaded before the first tumblers; we did. There are no specific ways to clean cases, never was. But clean is a lot different from the glittery polish many today seem to equal with clean.
Clean cases are the goal. It matters not if the cases are briefly tumbled or simply wiping the exterior down.
Obviously removing any dirt, gravel, spiders or such from inside demands a bit more effort but getting the insides surgically clean is meaningless. Few cases will require boiling in lye on the night of a full moon, etc, to be made clean.