I don't think so.
Saying o'clock the controller must infer and think of which way the aircraft is flying at that moment. ie your 3 o'clock could be my 6 o'clock etc
Saying SW is faster, then it's up to the pilot to look SW from his perspective, whichever o'clock that may be for him.
I'm not a Controller or any of that, but that's what I think about this.
On the other hand, if the Controller saw a plane following or approaching from the rear, I think everyone's heard of "Check your Six"