First I do soap and water to get rid of dust. Then WD40 with a toothbrush. That gets rid of the white stuff and sometimes very light rust. Then the Dremel tool wire brush - but be sure you never get Magnetraction near where you use the wire brush.
I work with mostly with 1949 and before. Yesterday I was working with a Magnetraction diesel and forgot to not get it near the wire brush area - looked like shiny whiskers on the wheels. Found that scotch tape will take it right off the wheels. Its stickiness is stronger than the magnetism of the wheels.