Delete Old Moved Backup?

I'm having quite the dilemma. I recently decided to wipe my computer but decided to back it up first. When I came to my Backup Hard Drive, I saw some old backups I didn't need. So, I put all of the backups into the trash. I then backed my computer and wiped it. After, I realized that every time I open the trash while the hard drive is plugged in, the old backups are shown. I am unable to clear the trash and remove it because some parts of the core data belonging to the backups refuse to be deleted. It would also take a really long time because of the hundreds of thousands of files needed to be deleted. I know that the directory for the trashed backups are /Volumes/Seagate/.Trashes/Trash/MacBook Air. Is there any way to delete there backups permanently?

Recent Questions...