I never looked back after using these, Gorgomyte.
http://www.gorgomyte.com/
it is THE product to make your frets all shiny again and truly shiny! Almost effortless, just a little rubbing and wiping, everything's good as new! Non-abrasive means you don't have to go all taping your frets.
It not only cleans your frets but if you have anything around that needs polishing, just use these and they'll shine like diamonds again. No kidding.
Nothing beats it, i've used PW fret polishing cloths which are essentially just super fine grade sandpaper (still abrasive mind you) and what not but these smacks everything hands down.
Anyone of you who loves shiny frets should try it!