I pronounce it the same way I’ve heard most Muslims around here (Dearborn, MI., the largest population of Muslims in the USA) say it and I’ve asked the ones i know what they prefer. So hete’s the consensus:
The letter U has the same sound as in book, look, or push so I’m not quite sure how to write it within the word without it looking like the sound in moose because of the double Os.
And the letter S is NOT pronounced like a Z. It’s a firmer S sound.
The Muslims whom I know are not that icky picky with their American friends because they realize that we didn’t generally grow up having to pronounce Middle Eastern words so when they hear it pronounced similar to the cloth (Muslin) they don’t get bent out of shape about it.
But that’s for the ones whom I know. I make no guarantee about how the more militant Jihadi types would react (since they find practically everything that we infidels do to be highly offensive). Fortunately I have never met any of those in person (at least not to my knowledge.)
But the ones I’m friendly with are cool about it. But they do appreciate when Americans make the effort to ask them what the preferred pronounciation is.
So that’s the story in these here parts anyway.