In some jurisdictions the sale of crack pipes (a/k/a vaporizers) is unlawful; in some others, not. Some claim that pot/hash, and tobacco, can be vaporized, which would bring them within the same argument as bongs and other pipe regarding having a lawful use; others seem to say that is baloney. It does seem to be the case that hash oil can be vaporized - after all, e-cigarettes work by vaporizing an oily liquid.
Actually, anything that can be turned into freebase (purified by dissolving in a heated solvent and collecting the precipitate) can be vaporized in a crack pipe - cocaine, meth, heroin, DMT.