Ok, will add my way of doing it.
I can safely strafe acks in the 190 from a minimum altitude of 5k. In the 109G10, i can do it as low as 2k.
What I do is I fly over the field, roll left and right while diving a little, select my target. Then I roll over, chop throttle and pull into a steep dive that leaves me with the gunsight before the ack. Then, I let the planes natural tendecy to pitch up let the gunsight walk over the target while I fire. This if followed by a quick roll to the left or right, and a near blackout pull. This is the critical time for some reason; pull too little, and you'll get hit.
Once over the critical point, I roll the other way, pull gently til outta harms way. Then up in an immelman and repeat.
Too bad acks firing doesn't show in films - in my example, the acks would seem to be firing just under me.