There's a website (and an app) with a list of all participating venues: http://www.die-nette-toilette.de/wer-macht-bereits-mit.html http://www.die-nette-toilett

There's a website (and an app) with a list of all participating venues: http://www.die-nette-toilette.de/wer-macht-bereits-mit.html http://www.die-nette-toilette.de/wer-macht-bereits-mit.html (in German)