Spit or Swallow?

OK, get your minds out of the gutter - or actually that is where they should be - but this is not an X-rated post but rather about the habit of expectoration, or spitting in public.
Having lived for well over 20 years in Africa and South America, where spitting is almost a way of life, you would think that I am immune to it, and accept it as normal, but I still feel it is a disgusting habit. I recall vividly the first time I saw someone spit in the street in the UK (which shows how much of an impression it made on me!) which was in 1963 while visiting the city of Wells - we were heading for the cathedral when a man approaching hawked and spat in the street. I was dumbfounded! Although we had just returned from 3 years in Angola where it was prevalent, this was the first time I had seen it in England - and was shocked to the core. In hindsight I realise now that the 60's was a time of mass immigration into the UK (and also the start of cheap overseas holidays to Europe where British tourists would be exposed to these unsavoury practices), and this was possibly the reason it started becoming commonplace.
My grandfather was asthmatic, having been gassed in World War 1, and  spent a lot of his life afterwards bed-ridden, and used to cough up copious amounts of phlegm, which he used to spit into lidded glass jars for later disposal down the (outside) toilet, so I guess from an early age I saw spitting as a necessary activity, but one that should include safe disposal of the "spit". I must add now that I have never been a spitter, I have never felt the need to dispose of excess phlegm that way, but have always been a swallower - after all it is a product that originated in my upper respiratory tract so therefore cannot be dangerous to me, and getting rid of it by swallowing means it enters my digestive tract for "disposal"! I have always carried a handkerchief (a throwback to my British upbringing!) and could use that to capture anything I might be reluctant to swallow!
When I first moved to Brazil I spent 2 years volunteering at a small local children's charity, with most of the children between 5 and 11 years of age, and I was horrified to see several of them spitting on the floor INSIDE the building! We quickly initiated a no-spitting rule, and offenders would be ejected for 24 hours, but it took a while to stamp it out. We told them if they really felt the need to spit to use the toilet, but some would spit out of the window! One persistent offender was a 9 year-old girl, who was a handful anyway, and I asked her why she was always spitting - her reply was that she had a "bad taste" in her mouth, and was hawking up phlegm to clean her mouth and then needed to spit it out. I asked why she didn't swallow it (or have a drink of water!), as I would, and she said that was disgusting!
We tried explaining that spitting was extremely hazardous to health, and spread diseases such as Tuberculosis, Influenza, Meningitis, and even the common cold, but this fell on deaf ears - spitting was so endemic that nothing we said could change their minds that it was the only way to dispose of phlegm. Spitting in public has been banned in many places around the world - the UK has made it an offence to spit in public since 2013 (in London you risk an £80 fine), but there have been relatively few prosecutions - however this has done little to control the practice. 
I will continue to be a swallower, and tut whenever I see a spitter!