On that note what is the easiest way to make dry mud/dirt. I have several of Mig's pigments, but have never tried the mud thing. I am a little nervouse because they say once the mud is on, it is there for good. I hate to ruin a good model because of it. Here is a picture (sorry kind of blurry):

If anyone has any suggestions please let me know.
Cheers,
Salvo