Look up "electrodynamic machining".
Putting a current through a bearing, especially when immersed in a dilectric fluid such as greese, is an incredibly efficient and rapid way to mill away metal from the surface of the bearing and suspend it as fine dust in the dilecteic fluid.
An arc through the fluid melts a tiny pit where it lands - mainly on the positive electrode, and vaporizes a path through the dilectric. When the arc extinguishes the vapor condenses with extreme rapidity (because of the low temperature of the surrounding dilectric) and the arc path collapses - with a cavitation-style shock wave. The shock wave blasts the dilectric into the pit and splashes the still molten metal (or whatever) into the dilectric, where it immediately congeals as nanoscopic grit.
Repeat thousands of times per second.
There is a whole machine tool industry built on this: Using the end of a wire as a drill, the side as a bandsaw, or a shaped carbon rod as a funny-shaped-hole drill. (There's a releated device called a "tap disintegrator" that is used to remove broken taps from a workpiece without damaging the workpiece by removing the center of it.) These are used for things like: Drilling precise holes in jet and diesel engine fuel injectors, cutting precisely-shaped strain-relief slots into cast tungsten jet engine blades (so several can be cast as a unit), machining the cylinders of diesel engines for cargo ships, cutting dies (in extremely strong metal creating a near-mirror finish), forming molds for casting plastic, etc. It can cut anything that conducts electricity (including diamond: By flashing a small amount of metal onto the surface to prvide the initial electrode then conducting through the graphite formed as the hole progresses.)
This was accidentally discovered in Russia in WW II: They were having trouble with lifetime of ignition "points" in engines for trucks and tanks. An engineer got the idea of oil-cooling the points. Lifetime went from months to days.
(By the way: I wrote the core of the motion-control software for one of those tools - the one whose first job was "bandsawing" those strain-relief holes.)