Actually, the best desulfator to use on AGMs is the electronic pulser type so you did the right thing assuming you had sulfation issues in the first place. Overcharging VRLA batts, rate or total, is bad because excess gas has nowhere to go except out the valve where it can't come back. I would probably just charge pairs at a low rate for a day or so and as long as you see something like 12.8VDC per pair I would put them into the bank and enjoy them.
John.........