I too always drain the tank. Then I pull the glow plug and spin the motor over to expel any unburnt fuel in there. I don't add any ARO if I am going to bash again that day or the next, but if it's going to sit any longer than that ARO is a necessity. Just put a drop or two in via the glow plug hole while you have it out. Spin the motor over and reinstall the plug.
Steve has a point about taking off the air cleaner to add the ARO in that he can inspect the filter at that time. I, however, don't like to remove the elbow for two reasons: that's a way bigger hole for something to fall into, and because I don't like having to take the chance that the new zip ties won't hold causing my filter to come off the next time I run. BAD juju...