A ultrasonic cleaner. OMG $40 and it did what hours of cleaning couldn't. It brought them back (my Microns especially) to out of the box, new like condition, except where my brushes are brassed up from use. But wow, it used to take me an hour a brush, to get them spotless, now it takes running a 4 min cycle (after every single part has been stripped down, yes that includes nozzle, air valve, MAC valve, and needle packing), a rinse off in the basket, maybe a quick toothbrush to knock off the big stuff, and a second 4 min cycle, lube up the necessary parts, and boom done. I cleaned my entire hoard in one afternoon.