That's about the only way to do it, just drag to trash, then empty the trash.
no i dont know how to do that, what i will have to do then is clean off all thedont do that. there are very particular permissions so i dont think you can trash it at all. if you can it would take forever to delete.
either format your external drive or delete using Terminal with root permissions if you know how to do it.
your other option would be to delete the backups from within time machine itself. looks like you can delete a whole volume at one time. don't know how long it would take, however.