The proper course of action is to get it deleted.  Flagging for deletion is one way to do that, on older posts with no answers, downvoting to -1 or lower will get it deleted when the cleanup scripts run each night.

[An older post on the auto-deletion criteria can be found here][1].  I think the criteria may have changed slightly, but for your purposes, if you come across an old question like that with a 0 score, downvoting is a way to get it deleted without putting the work on the mods.


  [1]: https://meta.stackexchange.com/a/92006/196495