Having spent far too many hours flying the DHC-6 Twin Otter, I can speak to this. The Otter has fully reversible props, and they will go to full reverse in flight, if demanded. However, the props are so powerful I always felt it would stop dead in flight and stand on its nose, and tumble... if you were silly enough to do that.
The technique if you were silly high and needed to get into a very narrow space was to twist the throttles and very carefully squeeze them back through the gate. It was like hitting a brick wall. The blades would act like a huge flat disc and the rate of descent was scary.
The one place you could use it was in stopping quickly when landing into a short field. As the wheels got to about a foot off the runway, pull the throttle straight through into full reverse and the Otter would sit down like a rock and stop on a sixpence. However... do not do this too high or you will be a steaming pile of rubble. Either way it was a trick to impress the bystanders. Stopping was never the problem, getting airborne was the constraint.