One of only a few attempts at this sort of manipulation, I've blended an image of a statue in Munich with a wall of peeling paint I found in Chatham Dockyard. The whole thing now looks like the statue is crumbling.
I think it works, the two subjects exchange qualities, disintegration for dignity. I'm a big believer that playing around like this is a great way to learn processing and manipulating techniques we can use in subtler ways in "standard" shots.
Tom