An apparatus and method for scarifying the interior surface of pipes, such as a sewer pipe, the apparatus including a chassis, a carriage coupled to the chassis to reciprocate along a longitudinal axis of the chassis, a shaft capable of indexing rotation coupled to the carriage, and arms extending radially from the indexing shaft and tipped in high-pressure nozzle assemblies. The method includes positioning the apparatus in a pipe and alternately reciprocating the carriage and indexing the shaft so as to scarify successive longitudinal swathes of the pipe surface until the desired circumference of the pipe section is scarified. The apparatus is then repositioned in the next section of pipe and the method is repeated until the desired length of pipe is scarified. The apparatus may further include a separable propulsion unit.