How about making everyone pay for trash collection in the annual property taxes.
Then have the supervisor follow the trash truck route and note any areas that they can Then dispatch a street cleaning crew.
Oh, I forgot, these adults (big children) need someone to tell them No, don't put trash on the ground when the trash bin is a 5 second walk away.
How about this. Punishment for littering is to pick up trash for 1 hour. 2nd offense 3 hours. 3rd offense 6 hours.
The public outrage would be comical why they have to pickup trash.
Here is a scenario. Keep the residential areas clean and then property values will increase, property values increase and more transfer tax is charged, your ROI would easily pay for the workers keeping areas clean.