Yes, you can just delete them.
What it does is it renames a file to ".del", then in a loop it slowly removes a part from it, so it makes it shorter, until it is all gone. If I read it correctly, it should erase by 20MB/s.
It would not be a bad idea to check when Enigma starts to see if there are ".del" files in the Trashcan, and of so, start the file eraser again.