...-like, random, Schneier, DoD.
See the project homepage https://libsecrm.sourceforge.io and the project Wiki in the menu above.
To wipe data that was left on the drive by using "normal" delete operations, you can take a look at WipeFreeSpace (https://wipefreespace.sourceforge.io), which wipes the space used by files marked as deleted (and other things, too).