So you don’t want your Amazon Echo to record everything you say. While it is true that you can deactivate its microphone, it’s not always convenient to do so. SparkFun has shared a video and guide that shows you how to build an off switch for the Amazon Echo using a Particle Photon and a MOSFET.
The off switch can be triggered remotely from IFTTT, using voice commands. You will be able to use Amazon Alexa to cause Particle Photon to remove power from your Echo. The project takes a couple of hours to complete.