Good luck, Mr. Rationalist

Is there any rationalist equivalent of “good luck”? I’ve tried a few variants, such as “work well”, “knock them dead”, “we’re with you” and certain situation-specific phrasings, but haven’t found anything that worked generally—though a hearty “may all the gods of Olympus be with you!” can serve. Not a vitally important point, but it would be nice to have something similarly supportive and yet accurate to say.