Some files or folders are not easily deleted, particularly when they are locked or when you don't have write permission.
You can use this option to remove Bin contents, regardless of privileges.
The Bin pane of the Files toolbar item allows you to securely delete the Bin contents.
The Secure Delete (3 passes) option overwrites every byte of deleted contents three times (with 0xff, 0x00, and 0xff again).
Therefore, these operations take a very long time. Wait for the task to complete.