[feelix]

writing random data on it, rather than zeroing it out, will avoid block de-duplication and successfully completely fill it up.

Here is a tool written for exactly that (although not intended for securely erasing a drive, it will have that effect too): https://github.com/rentzsch/stressdrive

[kalleboo]

Do modern SSDs not contain slack space for garbage collection? How can you guarantee that that also gets cleared out aside from "fill the drive with more data than it will fit and pray"

[nagvx]

Excuse my ignorance, but couldn't a cell that had exceeded its write limit be cycled out for a spare, thus permanently storing a portion of your data in a way unaccessible to any further writes, random-filled or not?