That may be so. However, the Macrobiotic diet, for example, is widely accepted to be useful for combating cancer yet people still don't wish to partake in it. This can be correlated to applying urine to ones face.
I am forced to do this on occasion, but I don't really mind because I wouldn't want people walking all over my carpets with their shoes either. If a person has marble or wood flooring in their house I think it's ridiculous to be asked to take off shoes though..