How do I permanently delete a poll and its results?

Go to OpinionCamp > Polls in your WordPress dashboard and delete the poll from there. This is the only way to remove a poll and its collected votes for good.

Deleting the block from a page does not do this. That only hides the poll from visitors and leaves everything intact in your library.

Deleting from the Polls screen cannot be undone, so if the results might be useful later, consider simply removing the block from the page instead and leaving the poll in your library. An unused poll in the library is invisible to your visitors and costs you nothing.