Errrm...nope. Just cloud and sky brushes lifted off DeviantArt, plus a cloud layer on top using colors sampled from the render...and then of course the usual pilfering involving layer duplication, gaussian blurs and various blending modes. The...usual.
Smudge doesn't exactly work with me... Tried it once, failed miserably and gave up. End of story, I guess.
EDIT: oh, and, uhm, one small detail - I don't use C4D. I use abstract brushes with my own little twist to make them look C4D-ish.