Default the "Empty Recycle Bin" only deletes pages older than 30 days (that is default by EPiServer).

To delete pages newer than this use the following stored proc:
editDeleteChilds'2'
where '2' is the pageId of the Recycle Bin.

This may come in handy when for some reason having large amounts of articles in the Recycler, and you dont want to wait until next month to delete them....