You claim I am autistic. I did not say that, and no doctor has ever said that. I guess you claim to be a doctor, too! My knowledge of fluid dynamics is not based only on what I learned many years ago in books. It is based on over 40 years of practical experience working with fluids every day, and I publish technical articles on the subject. Your "caveats" do not remove the fact that you said viscosity is essentially film strength, and you are also confusing film strength with film thickness, which is in fact dependent on hydrodynamics, even to the point that air, which has an extremely low viscosity, can produce a film thickness sufficient to prevent metal to metal contact under certain conditions. BTW, I am not working on agitating poop. Today I am working on a project for Shell Oil to design a continuous flow multistage reactor with non-Newtonian viscosity characteristics that change as a function of degree of reaction conversion. I calculate residence time distribution and stage efficiency, accounting for backmixing between stages.