Opposite rudder to aileron
Burtonwood Aviator:
Thanks, this sounds a bit more likely! The Mk III's in 1957 definitely didn't have spoilers fitted, and the simple checklist CISTRS (controls-instruments
-spoilers-trim-release-straps) wasn't valid for spoilers, it was only on the Sedberghs that you had them to check.
It also suggests another possible reason for us being told to put on a bit of opposite rudder in turns - to shorten our time in the air and get more launches in! There were quite a few of us on the course, and what with weather delays etc., it must have been a bit tight to get us all qualified for the 'A' and 'B' certs within the week.
I must admit I still have a lingering memory of being told the opposite rudder was to reduce height lost in turns, so I'm not 100% convinced, but your explanation of sideslipping to lose height as a substitute for spoilers seems a good one.