I would have to get my TX to get to the nitty, but there is an Airbrake function programmed right in the transmitter. Use that along with Pmix 2-3, one for each aileron. Turn Flaperon on, set that all to 100%, you need this first, then program your pmixes for each aileron up and down opposite elevator. after all that mojo is in, go back to airbrake and simple turn it on with the stick up a little, basically wherever you want it off idle. I program it so it all comes on using switch C on a Futaba Radio, thats the big one, top position. I use my TX with no dual rates, but just in case, I use all switches in the up position flying, just keeps things even when you 10 or more planes in the mix.
Hope this helps.