After decades of using a wet sponge (and even a rag paper towel shirt tail in the field) for sold...

[G+_Eddie Foy]

After decades of using a wet sponge (and even a rag/paper towel/shirt tail in the field) for soldering tip cleaning I finally tried the brass 'Brillo' pad style. 

 

I'm never going back!!

(you can get them for the dollar store, but they are only copper coated.  Get the real stuff, $6 will last you years and years)

[G+_Jason Marsh]

+1 for a high-quality brass wire sponge. It's so handy, and when you want to clean it out just roll it between your hands and give it a shake. Tons of little bits of solder go everywhere, but if you keep it clean you'll probably never need a replacement.