Re: hookah question
Nargiles of recent manufacture are designed to smoke tombac, jurak or moassel. You can also smoke crushed & spend can sugar out of one as well but I can't see the point in doing so. Prior to the rise of tobacco narghiles and the devices that proceeded them were often used for various illegal smoking mixtures but those sorts of devices are very different then what one could buy during the last few hundred years and are basically unavailable.
Various legal combinations of herbs can be used but from what I understand they are far too expensive and are poorly suited to typical, modern style narghiles. A fellow at another forum is making a moassel like mixture using herbs of various sorts but I have no experience with such things and I won't smoking anything that I don't fully understand chemically.
Bottom line is stick with tombac, jurak or moassel.