BleachBit deletes caches, cookies, and leftovers from a long list of programs, and it can overwrite free disk space so a simple undelete does not bring those files back. It is open source, for Windows and Linux. The project is run by Andrew Ziem. It became widely known after it showed up in a US political investigation. The tool is still just a cleaner.
The checkboxes are dangerous. Wipe the wrong browser data and you lose saved logins. Free-space shredding on a large disk takes hours and wears a solid-state drive for a benefit that modern SSDs do not honor the way a spinning disk did. Read each line. Back up first. A cleaner is not encryption, and it does not touch copies that already left the machine.
Use it for obvious junk, slowly. bleachbit.org
BleachBit’s preview is the button that tells you what will vanish. Use it. Skip free-space wipe on SSDs. Clean browser caches if you want disk space, and do not clean saved passwords in the same run. Linux and Windows builds are not identical in which apps they know. Update BleachBit so it recognizes current browsers. A cleaner from 2019 will miss today’s cache paths and still offer dangerous boxes.