dipping
n.— «The lawsuit claims that guards routinely engage in a practice called “dipping,” which Norman called a sadistic version of a common control measure. According to the suit, the guards take hold of the teens, twist their arms behind their backs, push them to the ground and rub their faces into the floor or slam their heads against the hard surface.» —“Prison rights group sues over Sacramento juvenile hall” by Hudson Sangree Sacrameto Bee (California) Aug. 28, 2006. (source: Double-Tongued Dictionary)