Sorry to be pedantic vctenderness but the yellow stain is 'tobacco tar', as nicotine is almost colourless and a considerably smaller component by volume of a cigarette. It is the tar that kills people, nicotine is the addictive part of tobacco. When you see air filters clogged and walls coated with this tar, it helps make the point for not smoking.
On thread: have only ever seen condensation, never a waterfall. The story of a partly sealed bottle rings true but I have not seen it. If it's common, I can well understand that CC would think any waterfall was a ruse.