[Lynne]

There is no automatic function in vbulletin that will grab all the attachments in a particular forum and allow you to delete them.

However, to answer your actual question of is it possible, sure it's possible if you write a query for the database to do so. And, if you write the query, of course you may set it as a cron job. This is more involved than just grabbing the attachments from the attachment table and deleting them though. You also need to find the thread and reduce the count of attachments in that thread and also get rid of any reference to the attachment in the post. In other words, it isn't just a simple query you need, you need a few queries written to do this properly.