have you tried mk27 torpedoes? they are equipped with a passive sonar device that allows them to home on everything which makes noise, even you!
though they are quite slow compared to other torpedoes, they are so easy to use on closing dds (or other targets) that it somehow ruins the experience of manual targeting. when a dd is closing on you, all you have to do is remain completely straight to the dd bearing, and fire away the little bugger. even when the mk27 turning ratio is quite low, unless you try to make them to turn on a dime, it will hit the target for sure.
dds are stunningly stupid too, they SHOULD hear through their passive sonar that a torpedo is closing in, but they do nothing to prevent that.
mk27s did exist late in the war, so is not an unrealistic option. But, as realistic as they might be, I prefet not to play with them.