Learn to be rude-I have found that people soon get the message and cease talking to you if you don't answer:
That's not necessarily guaranteed, in my experience. Some of the worst chatterboxes also have extremely thick skins, or else labour under the impression that you're listening to them even though you're not responding.
I have similar problems with interruptions, plus the fact that my day-job of writing software exercises similar mental muscles to writing fiction, so I'm often out of mental energy by the time I have the opportunity. So I frequently write late at night, when I can get time to hear my own thoughts.