Any tools to create cracks?

 From:  Zim3000x
7391.1 
I'm making a model for my 3d printer and I want the surface to resemble a stone surface so I want to add some cracks to the surface.
I've not had any success importing any filetype from moi to 3dcoat or mudbox so I want to do it entirely in moi.

I'm not artistic enough to create any kind of fancy surface as I've so far only made simple mechanical models so I hope there is a script
or something similar to mudbox sculpting. Is this possible to achieve without having to manually draw the cracks in 3d?