I like to strip the rusty parts & boil them in water for a bit. just like in the boiling stage of rust bluing this tends to help loosen the rust making it easier to remove with the steel wool & may tend to "Black" it just a bit. After the final scrubbing give it one more trip through the boiling water, be sure it is good & hot so will dry immediately & then treat with your favorite rust preventive.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra