I've used this twice. Both times, result was very good.
After asking her name, both times they were cute, young white waitresses, I ask "Is that Chinese?"
They both busted out laughing. It's ridiculous, both girls were so obviously not Chinese.
My table in each instance got great service after that and they were both very personable, had good banter, they both made a point to go out of their way to say bye when we left.
I didn't ask for numbers, but that's because I'm 40, they were much younger, and I've got a rotation of gals developing already. But it was fun & figured I'd share.