Digital cross processing involves manipulating the colour channels of your digital image to obtain the look of an actual cross processed photographic film. Traditionally the results obtained are very different depending on the type of film and chemicals used so this “digital cross processing” term seems kind of vague. As long as your colours are out of whack and the contrast is increased (that is a fairly constant characteristic of cross processing) you are golden.
In the old days when you would process your film in the wrong chemicals the results would be pretty hard to predict (I remember a completely purple toned photograph in a book about trains, accidental cross processing), nowadays you can tweak the curves until you are satisfied. Even though it seems kind of weak to spice up a photograph this way I wanted to see if I could do it too.