Sometimes the best solutions are the most obvious ones.
Evil scientist Dr. Doom (not that Dr. Doom) has developed a "grey mold disease." And just because he's evil, he unleashes it on Earth:
But the disease is an equal opportunity destroyer:
But the good guys capture Doom (no, not that Doom), and torture him into revealing the cure (editor's note: apparently, if you don't coddle your audience by putting up a neon "TORTURE IS BAD" sign in your story, you're ineligible for the Best Director Oscar. So, unknown writer and artist Richard Crater, you'll not be able to view Seth MacFarlane's no-doubt brilliant hosting in person.).
And that cure?
And it's from a book called Science Comics, so it must be correct, right?
Radiated water for everyone!!
From Science Comics #6 (1940)