Sorry for bumping this ancient thread...I have some experience with this subject...Well a hookah is a type of smoking device that is NOT meant to have weed smoked through it.
People use smoldering cow dung in some parts of the world. This isn’t done as much these days with the increased availability of charcoal even in remote regions. Even if it may be technically safe, which I don’t know if it is, I’m sure it would taint the flavor.
Many companies have tried to sell “electric coals” but so far none have been effective. These are usually metal gadgets that sit on top of the hookah bowl where the coals would go and produce heat using a coil. Sadly, the general consensus is that they do not get hot enough when you need the heat and then sometimes remain too hot and burn the tobacco.
I know that Fantasia (which sells shisha) has an "E-Bowl" attachment that can be used in place of regular shisha+coal on an ordinary hookah, but AFAICT, they're just heating up flavor/nicotine-infused glycerol inside of a cartomizer, so it's just a way of vaping regular e-liquid through a hookah.
Likewise, "e-hookahs" are just e-cigs that are typically longer and come with a button you have to press instead of being activated automatically when you suck on them.
I suppose vaping has slightly more similarities with using a hookah than smoking a cigarette, but I assume you're already aware of vaping, and that's not what you're looking for.
On Youtube, there are many useful guides on this subject, leave one of them here, maybe this is someone to come in handy in the future, Good luck!