How do carb restorers clean the outside of the carb?

Pep Boys has a cleaner on there chem. wall. It comes in a 1gal. can ( I think Gunk makes it). It's for cleaning carbs, it also has a basket in the can so you can clean the small parts to. I used it on the carb for my '56.... looked brand new when I was done. It didn't hurt the finish and it has a protectant in it. It won't hurt anything unless you leave your carb in it way too long.