> Obviously, this is disgusting.
Completely unrelated, but speaking of sharing spit with everyone else in the city. Here is what I would be doing in early 1980s in Soviet Union:
https://s-media-cache-ak0.pinimg.com/736x/51/4d/0b/514d0bce0...
Lining up behind a public soda machine. You paid 1 kopeks for just soda water or 3 for a little extra vanilla syrup.
The fun part is there would be just one single reusable glass. You'd turn it upside down and press and some water would sprays inside of it and "wash it" and then you'd drink your soda.
Here is a fan-site of those:
http://gazirovka.15kop.ru/gallery/#10
The funny part is. After all these years, I think it is completely disgusting and I would never drink or let my family drink from those. But at the time I can't say I was worried about it or don't remember getting particularly sick either.