A side note on my series on DBClean and data pruning. There are two different things you may express in days. The first is the retention for each pruning area. Each of my posts on specific areas discusses some of the details you need to consider when selecting a retention in that specific area.
The other is how frequently you actually run DBClean or the pruning script. My recommendation is that DBClean be run daily during the low point of database volume. I suppose you could go as far apart as weekly for the smaller areas or for a very small Commerce database. But depending on volume, you may need 4 or 5 hours just to remove one day’s worth of data – so if you wait until weekly, you’re looking at DBClean running for a day and a half solid. So your choice here clearly depends on your volume, database size, and requirements. But make sure you’re not confusing retention and frequency.