Here you go
What does this do?
Delete all of your messages at once via a link in private.php
What features does this hack provide?
* Delete all messages
What does this hack require?
Products Imported: 1
Template Edits: 1
3 Easy Steps
Step 1. Import the following product: product-delete_all_pms.xml
Step 2. Template Edits
Step 3. Enjoy the hack.