I don't think I dithered anything - what you're seeing is a roughened vignette, for that 'grunge' effect.
There is also definitely smoke there, but it's probably not as noticeable as the other plumes.
Yours is pretty good, it does look a lot like cross-stitch. Perhaps duplicate the layer twice, add noise, motion blur the first up, the second across, blend layers. The best blend mode seems to be 'Darken'.
It adds a little more 'thread-y' texture to it.