I would not run a red hot coil under cold or even hot water, it will change the molecular structure of the metal. They temper metal by heating it and then cooling it at a certain rate, it changes the behavior or the metal. I have not experienced any performance decline from any of my builds from age thus far. As far as cleaning the gunk off I would remove the wicking material and burn off what ever is caked on your coil, then when it cools gently scrub it with a tooth brush or very mild metal brush and rinse it off...Re wick it and game on!!