As a kid, my mom used to make yogurt popsicles, just by freezing non-fat fruit yogurt in popsicle molds. Totally different texture from "fro-yo", but totally delicious! Can't do that here, though, Swiss freezers don't have shelves/drawers tall enough to hold popsicle molds.

But yeah, churn-freezing sweetened yogurt should produce an excellent product.