"The soap has nothing to do with smelling nice it has to do with wiping your ass then stuffing the same hand into your food bag."
On solo trips, you can generally do away with soap. If you are not infected with anything, there is no reason to anticipate being infected with something through feces or urine. Sound's kind'a gross, but, this is a scientific fact. If you have ever had new-born puppys around, you know that it is common for them to eat their own feces. They do not die from this behavior. Nor does a mother get sick from cleaning up after the young ones. Even if a person were to have something already, there is only a few that can reinfect the same person...and it doesn't matter because that person is already infected with whatever disease/parasite (though some tapeworms, and other types can double infect...I am assuming a healthy person to start.)
It is Human to Human that transmits diseases. You cannot get a new disease from anything your own body produces. It is the other guy you have to watch out for.