Soldering sponge

I know how to solder, but on this forum I am constantly hearing about how its important to use a sponge. So one day I thought maybe you use a wet sponge to clean the tip. 2 words "rapid oxidation", time for a new tip! So I tried using another one dry to clean it off, all that happened was the sponge was burned. What do you use this for?
I leave some solder on the tip because I have heard that is good for it, dunno why.
Also is it worth it to have ajustable heat power?
Thanks for the help.

I use any old sponge lying around... although many times I end up using paper towel. I do not encounter this rapid oxidation you speak of... Unless its happening to the rest of my tip not tinned. And yes, I leave my tips tinned (with a little solder on them).

Just use a slightly damp sponge and swipe the tip on it to clean off excess solder. You don't rub the sponge on the iron with any force, or try to get all the solder off.

If the tip isn't sufficiently tinned, it can corrode (happens anyway with lots of usage). MCM Electronics sells a tip tinner/cleaner compound that works great. I've seen it carried at Radio Shack occasionally too.

keeping your tip tinned will save you lots of trouble. if you keep it tinned then you can use any sponge to clean the tip after heating.

Any sponge will work unless it's plastic, which will melt. I use old cellulose sponges.

Keeping the tip covered with solder (i.e., tinned) is a must, but if the tip becomes corroded and solder won't stick to it, then I let it cool and clean it off with brass wool. Then I coat it with rosin (Fry's has jars for $3) and fresh solder. I don't use steel wool or sandpaper because they can damage plated tips (iron plated tips last a lot longer), but this is no problem if the tip is plain copper.

Adjustable power or temperature regulation is good if you have to solder 4-6 layer circuit boards because the traces connected to ground or power can soak up gobs of heat, and may need 50W to melt the solder, while the solder on fine traces may need only 20W.