Electrolysis, vinegar, coke, molasses and the blood of everyone that bullied you in school all pretty much do the same thing, personally I prefer electrolysis, no smell, no stickiness, added bubbles for fun.
Obviously the issue is that when rust forms, it forms out of metal, leaving the pitting. Since this is a non-visual/structural part I'd just be cleaning it all up, and chucking some hardy paint on it, but most people aren't as slapdash as I am.
Your options for creating a level, smooth surface are to either remove good bits or add to bad bits. In this instance I'd favour the latter, add some filler or stopper (since the pits are so small) to bring the surface up. Alternatively sand the existing metal back to a good surface- but that's a real pain and you'll get very close to going through the metal accidentally.
Fill it and paint it bud.
