I like to be able to clean things as I go. That means I've done the proper preparation and am not scrambling around to get things in order during the brewing!
And I don't use a carboy often, but when I need to clean it, hot Oxi soak for a couple of hours followed by a wet rage stuffed inside and sloshed around. That wipes up anything that was stubborn enough to stick beyond the Oxi's ability to remove it.