specifications for attaching the nozzle assemblies to the main body 11 and prohibiting undesirable loosening of the nozzles or over tightening of the nozzles in some embodiments two or more circumferences of brush assemblies may be provided on the main body 11 in some embodiments the fluid pumped through the assembly 12 may comprise an acidic solution in some embodiments the fluid may comprise a washing fluid in some embodiments the fluid may comprise water as found in the region of the well site in some embodiments the individual nozzle assemblies 40 may extend radially outside the surface of the main body 11 in some embodiments the individual nozzles assemblies 40 may extend just to the exterior surface of the main body 11 in some embodiments the individual nozzle assemblies may not extend out to the exterior surface of the main body 11 in some embodiments the nozzle assemblies 40 may be movably mounted on the main body 11 in one embodiment the nozzle assemblies are seeded into receivers in the main body the nozzle assembly is connected to a piston type seat which is positioned in an inset in the main body during operation when the assembly 10 is positioned in the production zone of the casing and the high pressure fluid pumping is initiated the pressure from the high pressure fluid presses the piston assembly radially outward pressing the nozzles also radially outward and closer to the inside surface of the casing in some embodiments the brush assemblies may also be movably positioned with piston.