The power of white vinegar

yup. now we need a contest between the vinegar and the baking soda / battery charger methods

Already done it.
The vinegar is nice because you don't use electricity but you have to neutralize the acid in the vinegar either by flushing it with lots of water or using washing soda or baking soda.
Wash soda and 12 volts works a lot faster and the nice thing is you don't have to worry about an acid continuing to eat the metal.