If there are an excessive number of entries within the trash bin or if there are corrupted items within the trash it may not be able to be emptied as expected within the CMS UI. for this reason we recommend having the trash bin emptied periodically to avoid issues.
There is a scheduled job called "Automatic Emptying of Trash" that can be used to periodically clear the trash bin. If there are an excessive number of entries or a corrupted item within the trash bin the following database query can be used to clear the trash.
We highly recommend backing up the database before attempting any direct manipulation.
EXEC editDeleteChilds @PageID = 2, @ForceDelete = 1