My brother and sister-in-law (Westerners) lived in Cairo for a few years and tell a similar humorous story. They too would just set their trash and unwanted items out in the hall where it would quickly disappear.

Once my sister-in-law put out some clothes that included an old T-Shirt that had been printed for a family get-together celebrating her parents 50th anniversary. It had a large photo of her parents on it along with wording like "John and Mary's 50th anniversary" etc. etc. She thought nothing of it. But several days later while walking near their apartment, she was taken aback to see an Egyptian man coming toward them proudly wearing the T-shirt with her parents smiling photo on it.

And it seemed this was his favorite or only shirt. For months afterword, she'd see her parent's photo as the man went about his business in the neighborhood. She took it all in stride!