The soap guillotine

I decided to make a cutting tool with my father to make it easier to cut the soap straight. My father came up with the "soap guillotine". It works really well for making the straight cuts that I haven't been able to do. We made it out of oak and set the dimensions for the cutter to fit snug so that it can't twist or fall out. The structure of it really works well and I have set measurements so that I can cut 1", 1 1/2" and 2" slices. It is wide enough to accommodate any of my blocks of soap.
By the way, the black soap is my first attempt at using active charcoal in my soap. It is a very deep black color and is supposed to help remove oils from your skin. We will see.