Even If everything is non magnetic how do you plan to keep the gear oil from carrying the metallic particles back around into the gears and bearings again?
That oil carries far more metallic particles that you may think!
Good luck demagnetizing or finding something that is not already magnetized to some degree!
Just for curiosity sake I checked a bunch of old tractor transmission and engine parts I have around. Everything that is not cast iron has some residual magnetic charge to it!
I just used some fine cast iron dust from my band saw to check everything.
The dust it self is not magnetized but every bearing and tempered high carbon steel shaft I could Find is slightly magnetized!
Even a pair of bearings that I purchased brand new two days ago that have never even been out of my pickup yet still showed a slight magnetic charge!