Propylene Glycol - Beer will once again save the world.
FWIW, approximately 40 years ago, I attended a Rugby team party at university. It was an exceptionally cold night (-30°C) and I had a TERRIBLE cold/flu but chose to attend, as I it was my first year and I wanted to be ‘in’.
I drank LOTS of BEER and yes, I did smoke some pot at the party. At the end ofvthe night, I took a cab home. The next morning, the cold/flu was mostly gone. Like you, I put ‘the cure’ down to large quantities of beer, causing me to ‘pass’ the infection our of my system quickly.
In this case, ethyl alcohol did the trick, not propylene glycol.