Abstract: A method of scarifying an interior surface of a pipe to remove contaminants and corrosion products, using a vehicle carrying an attached principal arm that is pivotable and that has a nozzle assembly at a distal end thereof. The nozzle assembly has a plurality of nozzles mounted at free ends of associated nozzle branches, the nozzle branches being rotatable or capable of oscillation about a distal end of the principal arm. One of the nozzle branches and the principle arm are extendible to position the nozzle assembly adjacent a first selected region of the interior surface of the pipe. The vehicle moves down the pipe with the nozzle assembly rotating or oscillating, and applying pressurized fluid to the nozzles so that they each emit a jet that scarifies the first selected region. Once the first selected region is scarified, the principal arm is pivoted to position the nozzle assembly adjacent a subsequent selected region to be scarified and the process is in part repeated.