Glass door with structure - clean with a toothbrush

I have recently moved and in my new apartment all the glass doors are glass. The glass has a structure with many small squares and the previous tenants have apparently tried to clean the doors with cleaners.

Glass with structure should only be cleaned with water or vinegar water, under no circumstances may a cleaner be used. In such small wells, the cleaner is only in the "holes" and the glass looks dirty afterwards than before cleaning. The structure is so fine that the doors could not be cleaned with a rag. I sprayed the doors first with vinegar water and then cleaned them with a (electric) toothbrush. It took some time, but it was definitely worth it and the doors are clean again.

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