I worked for McDonald's in my teenaged years and saw the inspection report on one of the old-style machines. It was pretty horrible. The self-cleaning machine

I worked for McDonald's in my teenaged years and saw the inspection report on one of the old-style machines. It was pretty horrible. The self-cleaning machine was created for a reason. Unlike the fryers and grills the soft-serve machine is filled with dairy product, loaded by hand via human interaction, and just hovering underneath the safe zone temperature-wise.