When Don Camillo enters Brusco's barber shop to challenge him, he carries a three- days- beard. But before Bruscoe applies the shaving foam, Don Camillo is shaven cleanly.
Pay close attention to Don Camillo's hand with the glass of castor oil in the "Castor Oil" scene. He pours what is clearly a viscous, oily liquid into the glass. Before drinking however, his hand drops out of view and when he puts the glass to his mouth the liquid is all of a sudden clear water. Apparently drinking the castor oil for real was one step too far.