Early versions of Mac OS X had a strange issue deleting files that were locked under OS 9. When you throw such files away and try to empty the trash, you can get -43 errors or messages indicating you do not have permission to delete the files (even if you are logged in as root).
These two utilities, made possible entirely by Wilfredo Sánchez’s excellent utility DropScript, allow you to handle such files without using the command line.
DropUnlock will clear the OS 9 lock flags on files or files in a directory dragged onto it.
DropNuke will both clear the flags and permanently delete a file or directory of files dragged onto it.
WARNING: The purpose of DropNuke is to permanently delete files. As such, it must be used with caution. DropNuke and DropUnlock are provided without warrantee of any kind. By downloading DropNuke, you agree that neither DivNull Software nor DropNuke’s author are responsible or liable for any data loss resulting from intentional or accidental use of DropNuke.
WARNING: Dragging an alias to a folder directly to DropNuke will permanently delete files and folders in the original folder; however, aliases contained within items dragged are not resolved in this manner.
If you are unsure about whether to use DropNuke or not, don’t. Instead, use DropUnlock. In most cases, this will clear the “internal lock” on files, allowing them to be emptied from the trash properly.
Both of these utilities can be downloaded from the products page.