Side-slipping can be a good way of losing height in a low wing type. A Cessna with full flap and side slipping is not a sensible proposition as the airflow to the tail plane can be disturbed. Definately a way of spoiling your day.
Anyway I always tell students that if they have to side-slip then they've got the approach wrong. It should only ever be used as a last resort. >1000 ft/min descent at low level- not a good idea, best to keep it smooth and in control at all times. The reverse Bat out of hell approach makes me nervous!!!
