When an object with one function resembles something else, prepare for the eventuality that it will be used like that something else (say, monkey bars). Here, sand intended to be used for smothering fires is, well, still used for smothering fires – though perhaps different fires from those that the individual who placed it had in mind. View this not as a sign of disrespect, but as a broken market; demand existed for an ashtray that chance failed to provide.