Restroom standards are high even for public toilets. In Switzerland's large city stations, look for "McClean" restrooms. They have nothing to do with the red-and-yellow hamburger chain; instead, they're immaculate, sleekly designed spaces, with bathrooms, changing stations, showers, and a toiletries kiosk. Entrance is 1 SF or 2 SF (showers 12 SF) depending on the extent of your use. If you use the facilities at a bar, it's appropriate to buy a drink.