I use a blast cabinet. An abrasive media like fine aluminum oxide cuts faster than glass beads. It does take time but it goes rather quickly. For smaller screws and bolts, I screw them into a piece of wire mesh or screen. I replate my own with the 'Copy cad' (zinc) Caswell plating kit.
If you can find one, you could send your stuff to a local shop to blast/strip/plate them.
We have an ultrasonic cleaner at work to precision clean glass used for high-end displays. with the right chemistry, it'll clean grease, but not rust.