Policy on Trash Retention.

I'm having a battle with upper management in respects to the Trash folder.
Currently, we are using Retain to archive emails including the Trash folder.
My argument is that the Trash folder should not be archived and a policy should be in place, and set in GroupWise, to limit the number of days items are kept in the Trash folder.
Of course, if everyone used the Trash folder for what it was intended for, this wouldn't be an issue.
I made the point, "If you through something out in the garbage and your trash can is emptied every week, what is your expectation on getting that item back?"
I bring up the cost of archiving trash in respects to the additional time it takes to archive, the amount of disk space, etc., but I still can't convince them otherwise.
Now, they want to know what the policy is for other companies.
So, here I am begging for information.

If you could answer the following questions, perhaps it will help convince the "powers-to-be" to devise a policy!
1. Does the company you work for archive everyone's Mailbox Trash folder?
2. If they do, what is the thought process behind that decision?
3. Do you have GroupWise set to automatically purge the Trash folder, and if you do, what is that number?

Thanks for your time and input!

Stan