I may already have posted about this on one of the previous threads, but we did it on my FI course. And tried it too. I thought slowing down would work, but it really doesn't. What did was to decrease the throttle, while turning, since turning will increase the rotor rpm. You gradually circle and come down, but as far as I remember, you have to be very careful near the ground, and get it just right. I think you straighten out at the right point and then do a run-on landing; can't quite remember. But it does work.