Abstract: A chamber includes a door which opens to introduce a workpiece into the chamber and which closes to enclose the workpiece within the chamber. A workpiece support is located within said chamber and supports the workpiece such that a coated surface of the workpiece faces in a given direction. A liquid supply mechanism floods the chamber with a liquid to immerse the workpiece support. A pressure pulse supply mechanism applies a pulse of pressure to the liquid such that the pulse of pressure is transmitted through the liquid in a direction opposite the given direction. The pulse of pressure is incident via the liquid on the coated surface of the workpiece supported by the workpiece support.