Weird scooter

Saw a really weird scooter in Stockmann. (by scooter I mean a kick scooter, not a motor scooter). It had 3 wheels and was sort of V-shaped. I asked the saleswoman what it was for and she said that you are not supposed to propel yourself by pushing off the ground, like in a regular scooter, but by rotating your butt. Then she tried to demonstrate. Then I tried. Then she tried again. We rotated our butts like two helicopters but the damn thing just wouldn't move an inch. And now for some reason I still find myself wanting to buy this miraculous device, and wishing to find out how it works. So, my dear readers: have any of you tried to ride a scooter like that, did it work, and if yes, how?