Abstract: A rotating and telescoping cleaning system improves high pressure water cleaning of the inner surfaces of vessels or tanks. Vessels can be vertically divided with dividing plates with centered through-holes. Synchronized and controlled transverse and rotary movements of water jets result in a controlled spiral or helical cleaning track along the vessel walls. The water jets are directed at a pre-adjusted distance from the vessel wall and the travel speed of the water nozzle jets is exactly controlled allowing the removal of very hard deposits. One pass with the tool carrier with operating water jets along the length axis of the vessel results in a thoroughly cleaned vessel wall. The tool unfolds and folds inside of the vessel powered by the flow of the high pressure cleaning water.