An alternative to using the Destroy object on drop special function is DeskMan/2's Black Hole object.
To use the Black Hole, simply drop the object to be destroyed on the DeskMan/2 Black Hole object.
The Black Hole object has one option in its Settings notebook: Display confirmation dialog? If this option is set, any deletion using the Black Hole object will get a confirmation request. If this option is unchecked, then any object dropped on the Black Hole will be automatically deleted without further user action.