Canned whip cream is charged with Nitrous Oxide, or at least used to be. Those cartridges could be marketed that way to evade drug laws/regs or scrutiny. "They aren't for getting high. They are for dispensing whipped cream on a body and then licking it off." In my home there was a long standing head shop. At one point, in the face of growing pressure on businesses that sold "drug paraphernalia," they would turn you away if you said you were looking for a bong or whippets. You had to ask for a water pipe or nitrous oxide.