The Super Eraser erases rust- simple as that.
XK&T knives are very unlikely to rust- but i love Super Erasers so i bought a ton to have a few for myself and offer them to you as well, because i figure even if your XK&T doesnt rust, you might be a knife nerd with other knives (or guns) that do.
I go through about 1 a year, it is an eraser so like an eraser it wears down with use.
In my experience it helps create an amazing patina, leaving it behind when surface rust is removed.