I am sure that what Erstine has shared must be quite credible and you can blindly follow it. To top it, I just want to mention that etiquette is not something to be stressed about. If one applies a little common sense, has some sensitivity, then etiquette can be easily followed.
Ofcourse, there are some basic guidelines about what to say/ do ; but if you find out the underlining reason behind it, things will make much more sense and etiquette won't be only limited to interviews, or workplace, but it will become a part of your life.