https://www.youtube.com/watch?v=B28_VN8Q6YE&list=PLCC8AF94AC0F4311A
This is a series about a M1911 that was found buried in a ditch in TN. He used electrolysis to remove the rust, which took about 150 hours, and after a while it felt like the videos were lasting 150 hours.
I think your goal is to remove the rust and prevent further rusting, which you can accomplish by rubbing oil on the bare metal.