https://killtube.org/showthread.php?...ull=1#post8627
It uses the clientside files method - the player can simply delete the .cfg file.
Edited: I still use it because I find it better than nothing. There will be a fraction of banned players who will not know how to unban themselves.
I'm not sure if there is another method in this forum.
I may be wrong, but, cracked servers cannot get players GUIDs.