Interesting thread. I recently used vinegar and pieces of rusted barbwire to make some leather dye. After a few days the wire was clean and rust free. Decided to try cleaning a rusty flea market backsaw blade. After three days it cleaned up beautifully, but has a dull finish. Will try fine wet or dry to brighten it up. Just something else to tinker with. I also bought an old handsaw with a lot more corrosion that I am going to give the vinegar treatment. Cider vinegar is needed for the leather dye. Don't know if that makes a difference for rust removal. I may be trying to re-invent the wheel, but that's OK. It's fun.
Charles