None of the above

Some don't fertilize their mesembs at all, since in natural habitat they are in very lean soil/rocks, with barely any nutrients.
But I do see some people fertilizing lightly. I think if you do it 1/3 or half of the strength as other succulents and also much less frequent, it should work fine. But again they'll be fine without fertilization.

I wouldn't mist it with fertilizer personally, I don't think that would do much, so if you only water your Lithops by misting then I don't know if I could help... I recommend watering from the edge of the pot (around it) with fertilizer if you're not a fan of drenching them.