I’ve seen this done on do-it-yourself shows, but it doesn’t matter what kind of bread you use. I’ve always seen them pull off the crust, wad the bread into a ball, and dab or rub the soiled area.
I don’t know if it works, but here are some websites that recommend it.
http://www.manofthehouse.com/cleangen.htm
Finally! This one specifies using “balled-up” bread. It’s a site called “man of the house” so I guess it has to be explained. We women are presumed to magically know to do this…
A reason to click on this link - there is a spooky menu on the left side that follows you as you scroll up and down the page!