Start typing. Open console. pitch(), yaw(), and setfov() to your target. mousefire(1);
Worse: Send the command to start typing without actually starting to type.
You know what *would* work, though? An item.
A little flag that says AFK or CHAT on it, and takes 5 seconds of vulnerability to take out or put away. It occupies any potential weapon. It should automatically disable(Not instantly, though) if you move more than one unit on the x/y axis from where you took it out.