Grouper - Documentation
GrouperClearCache(stale = 0);
Deletes all of the files in Grouper's cache directory,
or, if "stale" is set to something other than zero, all files which have not been updated for the specified number of days.
The number of days old that a cache file must be to get deleted.
If omitted or set to zero, all files are deleted.
Example: (delete all cache files more than 3 1/2 days old)