Ich habe einen seltsamen Absatz in meinem Mietvertrag gefunden. Ich würde mich über Ihr Feedback freuen, bevor Sie dies unterschreiben. Wie soll ich das verstehen? Muss ich reinigen und bezahlen? Wie ist das legal?

Definitely not a good deal. The „broom-clean“ requirements don’t cover the full cleaning (which includes things like washing windows and blinds, descaling sinks, and deep cleaning appliances), but they get very close.

You can propose to replace this clause with another one giving you responsibility to carry out the final cleaning. You might still end up spending 800-1000 chf, but at least you don’t have to both pay and clean.

The question as always is whether they will change the clause and rent to you, or go to someone else. But I’d make a first try anyway.