Hi wingspan99!
>>What is the secret to getting a continuous torque roll?<<
Practice, baby, practice. :-) Other than that?... there are just so many things. A bigtime TOC pilot told me to make sure I had enough expo dialed in so that I wasn't over correcting... that may be the first place you want to look.
Beyond that... again, there are many things. One thing that really works for me... if I'm flying a Cap... I really concentrate on the elevator. I try to keep the pitch of the plane locked in at all times. That seem to work really well... and letting the Cap fall while torqueing really speeds up the spin. With an Edge I concentrate on rudder... the Edge's seem to lock in on pitch.
I bought another H9 Edge yesterday RTF w/ Saito 1.80. I forgot how much fun these planes are. It was radically underpowered... but the ease of which it locks into a torque roll lets you know that not all planes are created equal.
I've flown the Freestyle with a Saito 100... TR'n was not too bad... but it was pretty pitch sensitive, too. My friend had to rock the CG back quite a bit to improve its tendencie to dive out hard. It's not a bad plane... but IMO, it is not your best choice for learning to lock in to some serious revolutions.
TR'n is about 50% of how I spend my time when I'm flying... so we can talk about this ad nauseam if you like.