1) Scheduled search that runs every minute and writes to summary index.
2) Additionally, configured to alert "always" and email to firstname.lastname@example.org.
3) Expiration set to custom time, 1 second.
4) savedsearches.conf config for this search clearly shows 1s expiration value:
alert.expires = 1s
Expectation -- only 1 (or a few) directories related to this search in dispatch. Its ok if the cleanup job can't run often enough to keep it exactly at 1 second, even a few minutes would be fine.
Observation -- over 1000 directories generated by this scheduled search.