There is special pressure washers designed specifically for this purpose, called sewer jetters. They can clean the pipes leading from sinks and bathtubs leading to the tanks, even those at long distances, which is especially helpful in the case of industrial piping. The sewer drain jetters work at a high pressure, between 150-300 bar and 12-400 lpm. The pressure can be adjusted throughout the job as needed. These machines use a special nozzle that gets down into the drains to loosen and cuts the clogged materials that are obstructing the pathways. This essentially scours the pipes clean and then washes the debris back up to be removed, usually through a vacuum pump.