Shredo is a beautiful, functional file-shredding and privacy scan utility. It permanently shreds files, folders, and external volumes' contents to keep information secure and impossible for anyone to retrieve. Depending on security level and data-erase speed, you have 3 shredding methods at your disposal:
Shredo supports external volumes and flash drives, but depending on their size and method selected, shredding time many vary.
With a Privacy Scan feature - you can remove browser history, cookies and other privacy threats from your Mac.