You really need to make a big effort at cleaning the cleaners off/out of the metal/grain before you clear coat it
As usual, there are paint finish rections to consider too. Test out of sight. Clear lacquer is going to be thinnest, flattest, least noticable if you do it. ..most likely to react with present paint if you get sloppy too.
Polishes, stiff & soft toothbrushs, paint brushes (natural & synth), and stiffer, cheap "toss-away" tin-tube handled glue/flux brushes are part of my detail corner & crevass clean up arsenal.
Brasso and the Barkeeper's Friend products are about the best polishes.
Liquid? White vinegar(normally vinegar,flour,&salt paste). Lemon juice. Or 
live oil to penetrating oils /gun cleaning products, also nice for oil/ no-paint protection. Come to think of it "case cleaner" and vinegar and water solutions are used in ultrasonic bullet shell cleaning. (the Birchwood Casey concentrate is very risky too, but "Sheath" cleaner/protector is plastic safe, and is easy on paint if cleaned at the very least, and loves to eat at rust and some tarnish at least.)
Wax works well to protect too. Floor wax, car wax, bee's wax...hardly matters.
CRC electrical cleaner on a rag? (Ive never tried it near a nice finish, but it is a pretty neutral product)
Final cleanings leaving metal "too clean"; "dry", is seldom as good as "a bit oily ".
Ammonia based sprays belongs on glass and appliance enamel, or for grease/oil stripping, imo; that's it. It dries the heck out pastic by attacking it's oils...if not now, over time.
