Originally Posted by WernherVonTrapp

That's the method I would try. I've only accomplished a clean sweep twice in my history of this game and that was in the Stock Version (I'm not braggin') and, under the most favorable conditions. I would attack the convoy and immediately go deep in a direction toward the convoy's rear. There will (usually) be 1 DD that hangs around (stopped), protecting the convoy's flank. I'll then close, from behind him to within about 2000 yds and let a couple of fish loose. Once he's taken out, another DD will replace him in protecting the flank. It can be a slow, tedious, process and if the seas are rough, and it's night time, the conditions are ideal. I'm not too good with DTT shots like Armistead is so, this is the tactic I've come to rely on.
BTW, when they say "sink the escorts", do they expect you to take out all of them? Those ungrateful #@$&*$$'s!