Force empty the Trash:
At times macOS's trash can become impossible to empty. When this occurs Cocktail can force macOS to empty trash.
The SRM secure delete removes each file by overwriting, renaming, and truncating it before unlink-ing. This option meets the US Department of Defense (DOD) 5220-22M standard for securely erasing magnetic media. It erases the information used to access your files and writes over the data 7 times.
This feature is not compatible with System Integrity Protection.