Removing an item from showing up in autocomplete for custom field?

[Benjamin Peikes]

Someone misspelled a word when filling in a custom field we added of type "Text Field (single line)". Now everyone is entering the misspelled word because it shows up as autocomplete when people fill out the field. We've fixed this in all of the issue tickets.

Is there any way to reset the autocomplete so that it only uses values that are currently in use?