I just bought the K&N re-charger and cleaned my filter and air box as-well. I pulled the drain tube off the bottom rear of the air-box, then I just used a damp cloth to wipe down the air box while letting the larger particles go down the drain opening. I had to use a flat head screw driver to work the cloth into the tight spots while cleaning the box. That worked pretty well too. Just don't forget to reinstall the drain tube...