Based on the Emotiva product description:
“The ET-3 can also be configured to send trigger signals to up to three connected devices as soon as it is powered on. You can then plug the power supply for the ET-3 into any powered outlet on a remote controlled power strip or piece of stereo equipment. As soon as the ET-3 receives power, it will send trigger signals to turn on the trigger-enabled equipment connected to its outputs.”
…you would need to remotely control the power to the ET-3 in order to engage the 12v trigger outs. What method did you use John to remotely power on and power off the ET-3?