I run it daily with the days set to 30. I deleted the three example lines and my last line is
cleanup /home/dokuwiki/data 30
The entry into
1 10 DWcleanup su -s /bin/bash -c /home/dokuwiki/bin/dwcleanup apache
so that it runs daily 10 minutes after boot as user apache. The
su -s /bin/bash is to allow apache to run even though it is set to
I'm running a family server with DW used for storing family information, yacht management and workshop information. Obviously a commercial implementation would need to consider backup cycles to set an appropriate time.