Cleaning is good. Even better is to prevent the disorder.

This is a mailbox in our house where there are 55 apartments. In Central Europe, in the Czech Republic, it is customary to put in various mailings in the mailbox.
People will take them home with the post. They throw them out. Somebody recycles waste, someone does not ...
We (our "house self-administration") have placed a stand next to the boxes and have agreed that leaflet companies will be giving leaflets here. The flyer will pick up who wants.

The rest will end in bags that will be taken to a blue container for paper (Paper = Papír in Czech language). That's my job in our house.

Otherwise, advertising flyers would probably end up in containers for unsorted waste. Unsuitable waste will end up in a landfill or in an incinerator. The sorted is reapplied.