I did something like this for a Clunker 100 Chanllenge back in 2016. I used shop towels soaked in EvapoRust and wrapped with Cling Wrap on a very rusty Steyr Clubman:



I went from this:



To this:



I can't remember the details. I think I used a stiff brush on it a couple of times, and probably repeated the wrapping at least once, but as you can probably imagine I didn't put a lot of work into this one.