The reason the ATF and acetone solution does not take off the bluing is because it doesn't have the aforementioned acids in it, therefore it needs weeks to a month to remove the rust.
Solution for rust removal and freeing rusted parts
As shown below, the scientific test proven top solution is not an off the shelf rust or corrosion product, and in fact exceeds them all. And off the shelf products are far from equally effective. Kano Kroil tops them all in testing and some are just a flat waste of money.
Just a few representative tested products quoted in test results including the hands down winner: 50/50 mix of ATF and acetone. Cruddy guns are a piece of cake to clean with this solution.
Average load (Lbs) to release a rusted/corroded test bolt and price per fluid ounce:
W/O penetrant.................516 pounds … $0.00
WD-40.............................238 pounds … $0.25
PBBlaster ....................... 214 pounds … $0.35
LiquidWrench ..................127 pounds … $0.21
KanoKroil ........................106 pounds*… $0.75
ATF-Acetone 50/50 mix.....53 pounds**.. $0.10
* I’m not aware of KanoKroil removing bluing but may remove patina.
**Note: 53 lbs. was the load required to release the pre-corroded testing device. Recognize the ATF will not remove bluing.
SOURCE: April/May 2007 edition of MACHINIST'S WORKSHOP scientific test of penetrating products to remove rust and measure the force required to loosen rusted-solid test devices.
2007 edition of MACHINIST'S WORKSHOP - Google Search
They are all inferior to (well down the list in test results as can be seen above), and more expensive than ATF, good old tranny fluid. None of the other products have or will ever have the years and level of research and engineering to remove crud and/or rust, keep spotless, and sustain the life of a $4000+ and higher, piece of high tech equipment; your automatic transmission! It's also the least expensive product.
So if you have two parts cruddy or corroded together solid and want them apart, the only thing better than ATF, again as test proven, is a 50/50 solution of ATF and acetone. Nothing approaches its efficacy and performance, nothing. Just soak and agitate, period!
I became a believer when given a Sharps percussion carbine relic to "fix"; you know, a relic relative to firearms is a gun dug out of the dirt after years and years, a corroded chunk of steel, as in a bunch of parts frozen solid. That Sharps is now operational with new springs and wood, and the owner shoots it regularly. Factory stampings not completely rusted away are now readable again. It was soaked for two months in a sealed container that was also agitated by being driven around in the back of a pickup. The only thing that would speed it up is an electro vibrator.
Acetone has very 'light ends', in plain English that means it evaporates readily as we know. And will need replenishing unless the part with soaking solution is in a sealed container. A piece of schedule 40, 4" plastic drain conduit with end caps glued on both ends, long enough for the barreled action. Fill the container as full as possible to eliminate air space and evaporation. I also made the tube a little longer than needed, so after cutting off the cap to check progress, if not soaked long enough I could glue on another cap. Once it's sealed, confirm it won't leak.
The guy I restored it for actually bent the lever trying to work the action open when it was frozen/rusted solid! The action didn't budge. So I still marvel at how smooth it operates after the soaking treatment. The metal is so clean, a plain bare gunmetal gray. Like when Naval jelly is used to remove surface rust.
Then I fixed the bent lever.