I'd avoid isopropyl when other things work just as well. I take a Qtip and soak it in Galen's vodka 151 and take it into the well of the 510 batt and "screw it in" well making sure to clean that center post. A paper towel with 151 on the outside threads of the atty and the bottom center post but keep it in center. Everything comes right off - dries quickly and leaves no film and nothing bad to inhale.