As a Linux user I have been watching all the excitement over Bleachbit with a bit of bemusement since it is nothing but the windows version of shred (https://linux.die.net/man/1/shred) which every Linux install comes with standard.

Notably (not necessarily notable) the technique employed can be made less effective depending on what you are deleting and the filesystem it is on, which is why you generally speaking use it on the raw block device and not on individual files. Also it is less effective on solid state drives (increasingly common - has to do with internal caching and they way they actually store the data - http://cseweb.ucsd.edu/users/m3wei/assets/pdf/FMS-2010-Secure-Erase.pdf) than on the old magnetic drives.