Media seperator or any manner of strainer type thingy...
I have been using a large plastic bowl with holes drilled in the bottom...
It sits atop a 20L pail...
Small hole drilled in the side of the bucket... A few inches below it's top edge.
Place the whole contraption in the sink... Run water over the brass, stir it around.
Pins fall through the holes in the bowl and into the pail.. Water drains out of pail through the hole it it's side...
You'll always find a few pins left inside a few cases, but really.. Each case needs to be inspected before loading... I magnet helps me find and keep these errant bastards