it's pretty easy to deack, just point and shoot, but if you want to do it quickly and with no damage:
-Come in fast, as fast as possible without losing too much maneuverability, but not so fast that you don't have time to shoot less than you want on that pass,
-Practice point and shoot, you should (unless the plane is weak in the guns) be able to go very fast from ack to ack with just a tiny burst right on target.
-If you are not fast enough on the way out (out of the second last pass for example), don't bother flying out and back into it, just turn around and zap each ack, just make sure you are spending as little time with your nose pointed in a same direction.
-Practice changing direction using as little energy as possible, in other words as flowing maneuvers as possible.
You can both come from up high and swoop thru, or just skim at the edge, sideways circles shooting one at a time and never stepping into the perimeter of acks. The only thing that will never change is having to shoot and dodge at the same time, what varies is the way you do it relative to how much time you have to setup your vulch, or if you're clearing the field with an ackhugging con on your tail, or preparing the field for jabos a few minutes out, etc.