Re: Kotegaeshi, help please
Any technique can be easily defeated by someone who knows it's coming. In the O/T case, the friend is motivated (doesn't really want to let it work so he can feel pain, I don't blaime him), so he's blocking it easily by stopping the wrist flexion. And, Janet's dead-on, kotegaeshi is more of a movement-based operation of accepting uke's balance and momentum in a direction, the extending it out past where he thought he was going to go, combined with a structural change he/she isn't prepared to deal with. All happens at the same time, fall down, go boom. If trained ukemi, looks awesome. If not trained, looks ugly and often leads to something being broken.
But, I agree, don't try to show outside of class if you are still trying to learn it. I was tol that Kotegaeshi is a "20-year technique." So, keep that in mind, too. Not easy to really "Do" in a real situation.