Yes that is a good method to use! Sometimes if i get heavy repetition over large surfaces where i still want to keep the details small, i use two textures to mask with in dynamask, then I group the scratch/dirt- layer or whatever it may be and mask that group using different materials im dynamask. But usually blending two…
neeeeeevermind, i found it! http://www.zbrushcentral.com/showthread.php?177194-DynaMesh-Master!-unofficial-Information-Installation for anyone that's interested :)