I started the thread, then wandered off! Here is the effect I can get in Photoshop:
Brown layer at the back, photo next, then mauve, then white, and scrub off bits here and there.
Nice and Grungy! If it can't be done, it is easy enough to travel between programs. I just thought it would be a treat to have a rougher eraser. I've tried to import one, but no luck.