I attended Bell 206 training at a large GOM operator, (my company paid for me to go there, I didn't work for them) and when I got there I was shown the helicopter that I was going to begin training in, a 206 with fixed floats, I inquired as to why we were going to do autos in a float equipped helicopter since I never flew over water?
They said that from they have been told by my boss I spent a lot of time flying low and slow and that they were going to teach me vertical autos from the within the "dead man's curve".
So off we went, hover at say 250 feet, chop the throttle, vertical descent and as the world came up to us fastest than I have ever seen before, a sharp collective pull stopped the descent, lots of water splashing everywhere, chin bubbles partially submerged for a second or two (reason for a float equipped helicopter) and I even got to see a Crawfish sliding down the windshield once!, helicopter and passengers in one piece.
And there you go, almost vertical autorotation with no flare, just a collective pull to stop the descent, on a side note, the collective pull had to be extremely well timed, sharp without being abrupt, and I remember the collective almost touching the roof! I would never try this in skid helicopter since the chances of messing it up seem astronomical to me.