By dead shorting it brings the cells down and then equalizes the power between the cells, meaning is one cell is at .02volts and one is at -.02 volts they will transfer power between the cells and make box .00 volts... leaving the deadshort on for a week or so will allow them enough time to do so.... just discharging down to 0.00 volts per pack will not do the same thing because some of the cells may still be reversed.......
I'll bet that if you do this your cells will be just fine....
DEADSHORTING- discharge your cells down until they read 0.10 or less per pack not per cell, but stay above 0.01 per pack.... place a jumper wire between the positive and negative terminal and remove the discharge device.... allow the cells to set for at least a few days, a week would be better. start by charging the cells slowly, a good long trickle charge would be better.... once they read above 5.4 volts per pack then you can give them a good 5 amp charge to peak..... your pack may falsepeak a few times during the charge cycle........