The 3 Tools CNC Cleaning Machine is likely to be designed to deal with a fair amount of spray but with a pressure washer the spray is likely to be coming from angles that would not occur in normal use and doing so far more vigorously. Parts that can deal with spray raining down from above would be subjected to spray coming upward. CNC machining is a term commonly used in manufacturing and industrial applications. The term CNC stands for 'computer numerical control', and the CNC machining definition is that it is a subtractive manufacturing process. The 3 Tools CNC Cleaning Machine is very effective.