Does the Floo Network only work in English? What about accents?

Question

We know that you have to say the name of your destination clearly and distinctly when you're using the Floo Network. For example, Harry says "diagonally" instead of "Diagon Alley" and gets misdirected. This comment on an answer to How did Nagini enter the Ministry of Magic? says that "whether Floo powder recognises Parseltongue is dubious/doubtful." If Parseltongue doesn't work, do other human languages, or are they out since it seems to be a Britain-only network?

But even if only English works, what about regional accents in English? As this video demonstrates, you might be speaking clearly in your accent and yet be totally unintelligible to someone with a different accent. Do you have to speak well-enunciated Queen's English, or is not-mumbling enough?

Answer 1

As I don't believe there is an answer to this, I'll give you some reasonably well-informed conjecture.

Several times on this site (as I've started an answer before recently) we have agreed that intent is an important part of spell casting and magic in general. This is particularly clear in making spells effective and powerful vs simply existing but weakly.

Perhaps saying the destination clearly and out loud is merely intended to focus your intention. I doubt that the Floo Network truly works on any thing or any one actually listening in as this doesn't really fit the wider universe established since CoS was written and the network introduced. I would suggest that my theory on this is the fullest answer we will get unless JKR says more on the matter, but of course welcome other views.