Using an acid, even a mild acid like diluted vinegar, to strip rust will probably also eat good metal.
I personally like the electrolysis method. Faster than mild acids and less damaging to parts. Chances are you already have the battery charger, a plastic bucket and some scrap metal to use as sacrificial electrodes. All I had to get was some old fashioned washing soda as all we had in the laundry area was new fangled enzyme and/or oxi type boosters. And, from what I've read, there is nothing toxic to plants in the waste solution when you are done so it is easy to dispose of.