A method for preparing a workpiece surface utilizing two more fluids of differing
density and miscibility which create one or more fluid interfaces wherein the fluids
are chosen such that the solubility or affinity of one of the fluids is high for
a material to be removed from the workpiece surface while the other fluid has a
low solubility or affinity for the material to be removed. The workpiece surface
is treated by passing the workpiece through the fluid interface. The two or more
fluids are preferably dispensed into an apparatus and allowed to settle into two
or more predominant layers separated by an interface. Surface preparation techniques
which may benefit from the present invention include etching, cleaning or drying
processes and the like.