Currently it does not do what it should. As the auther mentions, it may work on the first search, but not on subsequent.
It is not necessary to use encrypted.com, just add &hl=en to your search term, e.g. https://www.google.de/search?q=search+term&hl=en.
This should be done by the addon.
You can make a simple bookmark with this search term:
Then add a keyword in it's properties, e.g. "g". Then you can search using your address bar, by "g search term".