Pulsing doesn't mean glowing white hot for an extended period. Barely red under dim light for just long enough to see hot spots is more than enough. The pulsing isn't to clean the wire, it's to make sure it isn't shorting itself out. (99% isopropyl from Shoppers/Rexall/whatever is how you actually clean the wire. Heat just gets rid of whatever you added when you installed the coil, and it doesn't take much to do that.)