I had used it the other night and had to pull it out from the other bathroom in order to make it work. It was dirty and she putit in the dishwasher with almost nothing else, but I’m a little fucking skeeveed by it.
Edit: thanks all. I’ll run it again with vinegar at the hottest and feel better about it. No divorce. Thanks for your help.
That is completly normal in Germany (and most of the rest of this world). Only very few buildings have separate grey water lines.
A"siphon" or "trap" is why this doesn't cause a smell problem.
Normally a separate grey water line is only used, if the grey water can be used on the property. A separate public grey water collection system is almost unheard of, except in some scientific project related developments (there has been some research into this, but it hasn't proven to be a reasonable solution, for now at least).
I might have to add that I am a civil engineer specialiced in urban water management. :)