Im pretty sure he meant taking the cables off the battery and holding the cable ends themselves together. What this does is discharge the capacitors in any ECMs to reset them to a normal flash without any learning adaptions included. The same thing happens with the battery disconnected for an extended period of time.
If the battery charge did not raise above 12V with the battery sitting by itself the you either didnt put enough charge to it or it has a bad cell(s) and needs to be replaced. Not many cars, and definately no computer controlled one, will start with less than about 12.3V from the battery.