hmmm, I just made very effective of a slip in a 172 to make it into a runway when the engine 'weren't right'...
used it to lose about a 1000 surplus feet, just pushed the left pedal as hard as I could and steered with the yoke.
Main thing with a slip is to not accidentally pitch forward and gain a load of airspeed, and just be real steady with it.
It can be a great tool in the armoury when you need it, and I gave silent thanks to my instructors (glider and power) when I got my stricken 172 back on terra firma...
Ohhh, the DRAMA !!!!!