As someone who has worked a few service jobs: oh god please don't start a conversation with me if I'm on my lonesome. This advice needs a huge sticker that says 'mileage may vary'. Not everyone wants the silence to be punctuated with smalltalk.
Needless to say that being polite is out of the question here, and that I am sure that the author's intentions are not what I just commented, but I can't help to read it that way.
I would agree that "please" and "thank you" can take you far, however you don't just have to address them to the janitor, it's for everybody.