See, I thought that using salt is illegal! But that's what Münster city has been doing all along. And they never made a secret out of it. On the contrary, now the people responsible find themselves criticized because they ran out of salt and have stopped using it pretty much completely. Kritik an der Stadt: Ohne Salz blieben Münsters Straßen bis Freitagabend spiegelglatt
They stopped doing anything, in fact - there are a few half-hearted handfuls of gravel on some of the roads, but nothing else. I wonder if the city even owns a snow plow or the like.

Even in stores it's almost impossible to get anything other than salt to clear the sidewalks. (Except now of course you can't get salt any more either because it's sold out.) I always found it baffling that not only do you not get fined if you use salt, they encourage people to do it.