Absolutely +1 on the cheap tool. however, when I got ready to do my tires I didn't have the tool (forgot), wasn't going to take the time to order one or go to a bike shop. so made one on the fly.... tried the double nut, someone had tightened the **** outa my axle before I bought the bike, double nuts wouldn't hold, had to weld em....... now I have a tool...... home made, $0, works great. it now resides in my tool box.
Just adding another alternative to all of your excellent ideas