The alky is real porous, so it absorbs water real easy. Then it evaporates and leaves all the water laying in your motor where the alky used to be! causing your bearings to rust and take a poop!
For a purge bottle. I just use my old coolant overflow bottle with the old tee fitting from the stock fuel lines. On hook your fuel lines from your tank, hook up the purge bottle, fill it with gas oil mix, and fire the bike up. Run it till it gets real boggy like, it smokes like crazy. Shut her down, unhook the purge bottle and hook your fuel lines back up. Also, you can either fill your tank all the way to the top with alky and plug the vent, or you can drain the tank and leave it dry till ya wanna run it again.