Contaminants are removed from oil well components by high pressure jets of hot water. The water and removed contaminants are retained and moved by suction to a holding tank for environmentally acceptable disposal. Rod strings move through a housing assembly which is attached to the pumping tee of the well. Nozzles in the housing assembly apply the water. The water and contaminants are sucked from an outlet in the lower bell cap of the housing assembly. The nipple in the bell cap extends upward at least to the upper edge of the bell cap to prevent water and contaminants from entering the well. Suction is provided by a suction pump which draws air from the holding tank. To decontaminate a tube one end of the tube is sealed off and a tee fitting assembly is attached to the other end. A nozzle fitting on a hose (termed a snake) propels itself through the tube as it removes contaminants. The contaminants and water from the nozzles exit through the tee fitting into a hose to the holding tank. All of the apparatus except the housing assembly and snake is mounted on a trailer.