I concur with all the above, don't mix chemicals unless you or someone you trust has done some exhaustive tests.
My formula for cleaning up action parts, irrespective of how dirty they are is a 10 minute boil in dishwasher liquid solution, same concentration as it recommends for really grubby dishes.
If it doesn't get all the crud off in one go, I rinse and give it another turn.
I then work over very gently with a Dremel with wire brush to remove loose rust, avoiding all areas with original finish.
This has never damaged the fragile colours under the crud and has produced several myrical results on guns thought too far gone to restore.
