Hello Patrick,
Yes, you can reset the number of cleanings. Refer to the steps given in the technotes below in order to do so:
How to reset the statistics on the cleaning slot
http://support.veritas.com/docs/240836
How to reset the cleaning statistics for a standalone tape device in Backup Exec 7.x, 8.x, 9.x and 10.x
http://support.veritas.com/docs/231561
You will need to schedule the cleaning jobs after a certain interval, eg. one week. Refer to the link below that will guide you in this process:
http://support.veritas.com/docs/255442