[simtel20]

The size of the clientele for many of these things probably would have been much smaller without the illicit uses, and they probably were created without illicit motives. Once there is demand, however, the further use was probably quantifiable as legit vs. off-brand use and even if one maker of glass tubes (for e.g.) stops because they're useful as rock pipes of some kind, someone else would be happy to pick up the slack.