This is a lot easier to take care of preventatively, starting with new rotors.
And I don't think you'll ever be able to keep the holes 100% rust-free any how..
Same ol' same ol'...remove the rust using chemical and mechanical methods, then coat with something, in this case somethign heat-resistant.
I'd just get new rotors plated, but IME that can be kinda hit-or-miss (my last two sets didn't turn out Autopian-quality by a long shot).
Heh heh, most of the time I doubt it'll turn out as well as that Viper's rotors already are

Hey, if it's driven it's not gonna be 100%.
The best approach I've heard of was having the rotors plated with electroless nickel by a custom-plating shop. A guy here did that on his show-quality Benz 500E (good enough that MB borrowed it for a display), but I never heard how it held up long-term.