#8
By the time you're taking an accent that was created for bombastic comic effect in a slapstick film, and recommending it as the correct pronunciation of something someone would like to insert into their English sentence, I believe we've lost the forest for the trees.
/tromp loy/ is perfectly correct.
I don't think the French is like äu. I beleive that it's pretty much a diphthong of German ô and (Continental) i, which I don't think exists in German.
I'm a little out of my depth here, however.
There's a reporter on NPR who pronounces Chinese names with the (I assume) correct tones, which makes them sound unlike a first name - last name combination to the ear of an English-speaker, or at least to the ear of this English-speaker. It is possible to take these things too far.