Cerakote is pretty stout. I've been using it on firearms for a couple of years now. Just for giggles, I refinished my wife's compost/garden shovels with it last summer and it's holding up very well. As an added benefit, the coating is almost "non-stick" and it exhibits much more lubricity than the bare steel. The edges show a little wear, but otherwise, they still look pristine after a rinse with the water hose and I don't have to worry about rust/corrosion.
I think it would work quite well on knives/machetes.