I've prepared my feet for my unsuspecting student by neglecting to wash them for a week. And the black nail polish is almost the same color as my extremely dirty and sweaty soles! When I remove my shoes the stench overwhelms my student and I shove his shrunken tiny face between the space between the last two toes of my bare foot. I'm very happy to see my tiny victim suffer from the intolerable stink: he's literally by the nasty aroma and his face almost appears to melt from my acidic-smelling feet!