Here's the setting in the yaml file:
Note that the value is in seconds. I just set mine to 60, and all the temp files are now being cleaned up after every execution VizAlerts is making. Note that it runs the cleanup process at the start of the VizAlerts main thread, so if you only ran it once, you won't see any effect until it runs again. VizAlerts is designed to be run every minute, so if you aren't doing that, unexpected results may be the outcome.
Thanks for confirming Matt, that's what I was looking for. Previously in 1.1 I would only see entries in the temp directory for alerts that were actually triggered, so I thought they weren't getting purged due to all of the "MainThread" entries in the temp directory created every minute. After taking a look I'm seeing files 24 hours old cleaned up after each 1 minute run.
Ah yes, that's because we moved to a workbook-based configuration rather than the SQL query in the yaml file, and just used the existing code to pull the CSV down, pretty much like any other actual alert. It looks weird, but not only do we get awesome flexibility with the configuration of different alerts (that you can alter via Web Edit even!), but having those CSVs there also helps troubleshoot if an alert seemingly does not fire when it should.