Their secret to clean bathrooms evidently was never passed to the Chevron gas station down the street from me....
The secret is bleach, frequently and mercilessly, in an impervious surfaced space, no vinyl, no wallpaper, no sheetrock. Nothing but smooth ceramic tile and gloss oil painted lime plaster walls, so you can hose it out if need be, and there is a need more often than you’d think in a public restroom. People are pigs, especially when they know they’re not going to be cleaning it up.
Oh, and ventilation, plenty of that, being enclosed with such an amount of chlorine fumes will make you see stars and pass out if you don’t get fresh air and quickly.
If a toilet seat is cracked or chipped, it’s going to harbor some nasty microorganisms regardless of how clean the rest of the restroom might be, don’t use it or carefully cover it before using.