Ian, we have to give the guy some slack. He doesn't know how to drive a car with a manual transmission.
Atleast my car (A mk 3 Golf Variant) slows down more rapidly by using engine braking. The hand-brake only locks the rear wheels and then it's skidding time. No matter what the weather, be it dry or wet or snow or ice.
Now my previous car (-84 Saab 900) had the hand brake act on the FRONT wheels. Yes the actual wheels on the front. The ones that turn. Even it slowed down more with engine braking.
You might want to use the hand brake to actually stop but for slowing down the engine is much better.