We were certainly taught it on the Sea King OCU when I went through as a student. We were not taught it at Shawbury. When I returned some years later on the Sea King OCU we taught it as part of the height climb sortie [10,000ft] but again only to the incipient stage. I think the early sorties teaching it were very much along the lines of " Did you see it? No! Right lets go home?" I am pretty sure it was taken out of the syllabus not too long after though?
like Crabb, I have only encountered it [for real] when others have put me into to it inadvertently. What I did find was that sat in the co-pilot seat because you had expereinced it you could see it building and warn people. The most famous last words were " no chance, not in this old bus ....... oooooh!" - You know who you are! Falklands, 2000ft over the airfield! - and how low did we go!
[I am sure we introdcued CRM training just after this!!!]