Rollers!
I too find Insiders to be much easier, since no rudder input is necessary. I was told they can't be learned on a LT-40 Kadet. O Well! Now, insiders are like second nature. I've tried outsiders, but they do seem to require rudder input in order to complete them in a controlled manner. On insiders with out rudder, the elevator is what carves the circle. It's just a matter of timed application.
A very helpful article on the subject was written by Dan Wolanski in the March 2000 MAN. It breaks the manuever down in such a way that helps you learn it in individual components which makes it easy once you put all the components together. It seems like Dan likes outsiders better also!