I think the parent was oversimplifying a bit, and it looks like you took his answer a bit too literally. What is important really here is to establish a contact with the person before asking for service. Anything goes - bonjour, hello, a smile, a nod (works for me very well). Just try to put a bit of your emotions into this (presumably: you are a stranger in a foreign g country not speaking language and needing assistance), and the rest will go accordingly.