My white gold wedding ring gets sorta dull looking sometimes (it has been five whole years!) and to brighten it up, I’ll pour a glass of Coke and drop it in! After sitting in the Coke for a little while, I rinse it off and put it back on my finger. It is much less dingy looking!
The Coke works some kind of magic eating away all the scruffiness… makes you wonder what it does to your insides when you drink it, huh?
Disclaimer: I take no personal responsibility for jewelry anyone else decides to place in Coke!