I made mine pretty much "Idiot Proof" buy putting it on a chennel with a momentary switch. I have a radio with assignable switches. It does not keep the switch closed, just when I pull the switch. I have the standard kill switch on the plane, and also have the trottle set close completely at low trim. If you have a "throttle cut" switch on your transmitter, you may be able to program to a seperate channel.
You can also set up a switch that is tripped by the throttle servo or pushrod at low trim.