Hi @Anonymous User
I am not aware of any other way except pull the plug out on your box or look at a mains adapter switching plug with a remote controller that you can power the box on or off from your sofa.
Or if your TV supports a USB 5V 1A port and the port drops power when the television is in standby mode, then maybe consider the NowTV Stick.
Though i prefer the NowTV boxes personally myself (apart from the white box) over the Stick.
@Anonymous User @schnapps
This is what I use to switch my Black Box off, when not in use, and on , when I want to use it.
There's a two socket version of this mains extension as well.