I would be curious to know what would happen if you put a carbonated/soda drink in it.
You could probably put a carbonated drink on it, though...
yes it does, you just pour in/out from the bottom.
That's basically the whole novelty of a Klein Bottle https://en.wikipedia.org/wiki/Klein_bottle
Would it be more correct to say that there is no inside surface? And it was just a pun that went over my head?