FST's in completion types

I have a completion field that I use to suggest city names across the world. I use the payload to return metadata (id's in a native relational DB, and a formatted output like "City - state"). Recently the consumers of the suggestor asked me to replace the "City - state" by "City, state" so I reindexed the documents with those values in the payload for the completion field. The problem is that now the suggestor returns both the old and new form, so I think due to the nature of the FST being kept in memory, I don't have an easy way to flush the old recommendations...Can I get away without a restart ? I tried a _refresh in the index to no avail, so wondering if there is a special way to clear the old recommendations ?