How to Permanently Delete History – Is It Really Possible? or Can Someone Explain How to Permanently

Lol I feel you on the paranoia. Honestly, how to permanently delete history depends on what you're deleting.

Browser stuff? Use CCleaner with secure deletion (7 passes).

For files, Shred on Linux or File Shredder on Windows.

Phones are trickier—Android needs encryption before reset, iPhones are better with "Erase All Content."