I don't think that method works (or is reliable) with a typical sampling DMM. From what I remember, the balance is essentially a symmetry adjustment. If you have a traditional analog meter this may work ok, but I doubt anybody here doing this has one. The way I posted is essentially the most foolproof because it verifies that the currents through each bank are the same before moving on. The way Ampeg posted is faster and easier but if there is a condition where there is circuit unbalance, it could give a misleading result.