I'm using a salad spinner I got at Goodwill for a couple bucks to separate the last few steel pins from wet-tumbled brass. I use the spinner as a shaker, not a spinner: brass is too heavy to spin with this gadget, and the plastic gears can't take sudden reverses to offset centrifugal forces.
I use a Frankford Arsenal tumbler, Armor-All Wash N Wax & Lemishine, a gold sifter pan on top of a 3-gallon bucket, with a 5-gallon paint strainer bag in the bucket to catch the pins.Use an FA magnet to snag the few stray pins.
I've seen a YouTuber who uses a finer-mesh sifter on the bottom to catch pins. I don't think that way would be as easy to get the pins back into the tumbler without spilling as using the paint strainer.