I've acutally been thinking about you chopping a rat in half quite a bit....here is what I have come up with. The whole purpose is to reduce the size of the rat right? Well, rats being longer than they are wide made me think of this. How about gutting the rat like you would a deer. Make an incision from pelvis to neck, gut it, then wash it out and dry it with a hair dryer. You still keep the majority of nutritional components from the rat....granted some of the organs are lost....but your snake should find it much more managable and you won't have guts everywhere.

What do you think?