Sniper... as usual, good gouge!

Adding to my notes for SH4.
I have used decoys successfully if the DDs are closing fast and pinging like mad. In the dive I'll go to flank (perhaps crash diving depending on depth), punch out a decoy or two and run that heading for a minute or so, then while slowing to 2 kt I use the extra energy to turn to a new heading balancing the direction with maintaining a narrow aspect to the DD...
Given the freedom to do so, I try to time the decoy/flank maneuver as I approach the thermal layer, timing the power reduction to coincide with passing through it. Has usually worked, but occasionally need to "Dance With the DDs" to escape a particularly talented acoustician.
With respect to how effective DD acoustic differentiation is, does heading in the convoy's direction diminish their detection?
Cheers!