The idea of a rolling harrier is nice high alpha rolls that are nice and axial. If you are using low elevator and aileron rates, then you are doing something closer to continuous rolls vs. rolling harriers. When you slow the plane up in high alpha, then those extreme aileron rates won't seem so extreme. Same with the elevator although sometimes full deflection with too much power will pull you into too high of an alpha (verticle). Experience will fix that. The best tutorial for this maneuver is on Flying Cirkus just like th others have said. Full 3D rates! And if anyone telling you how to do this maneuver says you can do it without using rudder, please don't listen to them.