Easy Performance question

What is the most efficient/effective way to delete documents based on Date 
Created?  I want to build an agent to delete all docs in a database > 31 
days old. 

I need an agent  to purge docs from my Mail Journaling Database. The 
Journaling option to Purge and Compact at a 31 day interval could result 
in a ~20GB database before the 31 day cycle kicks in .   I don't want to 
deal with that

Using the Agent Builder causes an error with the simple Document Selection 
option.  It cant build a Temporary index that big - and I don't want to 
FTIndex the whole thing.

Should I ....

Have a hidden categorized  view ?

Build a Document Collection?

A.J. McCartan
Enterprise Messaging