For what it's worth they now make smokeless hookah. It's basically stones that are pressure injected with flavored vegetable oil, and they're free of tobacco and nicotine.
It isn't vegetable oil. Hydrocarbon oils would be dangerous to inhale potentially. This would be closer to ecigs than a regular hookah and hookah is safer than cigarettes because you are vaporizing versus burning. Still this is probably a bit mroe dangerous than ecigs because you still have burning coals.
https://www.google.com/search?client=safari&hl=en&q=...
I've never tried them, though there are a few different brands you can find on Amazon, some of which actually have pretty good reviews.