Well, let's gather all my high-school French, and memories of my family, and freinds who are French (and all of that experience and a dollar still won't get you a cup of coffee), theoretically I think (notice the disclaimers) it should be sow (like what you do with a seed in the ground, or sew with a needle and thread, not a female pig) tuse (rhyme with use). Think in terms of "au" -- as in cafe au lait, roast beef au jus, or anything au anything else, very common cooking terms for the first syllable.
One thing, though, that I've learned about any terminology from any language, when you are in a community, pronounce it the way they do if you want to fit in. For example, I know darned good and well that Quebec is pronounced close to Kay-Bek, after all, my entire family is from there. But then, you get tired of people thinking you're pretentious or even not knowing what you're talking about. So got to saying "kwuh-bek", just to be understood. Then my best freind's mother looked at me sternly and said, "Claire, you know better than that!!!!" Pardon, pardon.