For the home shop I highly recommend:
https://www.lowes.com/pd/Zep-5-gallon-Degreaser/3621248
Scrape off the heavy stuff, soak the parts in this stuff full strength, use a plastic or wire brush to scrub the parts as you take them out, rinse parts with water, and dry.
A couple of years back I restored a Sheldon lathe, attached are pics of the headstock casting before, and after soaking overnight.
The pics of the backing plates I did just a couple of weeks ago using partially exhausted cleaner. The rust is just light surface rust and is easily removed with a wire brush.
Use chemical gloves and face shield/safety glasses. Do not use on aluminum. Dispose of properly when exhausted.