As a case in point, I scrounged about 300 pieces of 9mm brass, and loaded it. Check it first. Only works for single stage loading. Not necessary, but it is nice for rifles or other ammo where accuracy is king. This is by far the easiest way.
Tumblers use crushed corn cobs or walnut shell and they vibrate to clean cases.
They work fantastically. Brass stretches legthwise a little when fired, and if it isn't trimmed every few loadings you will eventually have problems. For single stage loading. Tips Avoid nickel plated cases. They look nice and stay clean, but the nickel has a rough surface inside the mouth that can make bullet seating difficult.