Answer: We saw a photo of a neat device for this purpose in the January/February issue of the British magazine, Quality Concrete. Used at Smith Concrete's Stratford on Avon plant, the device consists of a perforated spherical tip that screws onto the end of a wash-water lance. The tip is about the size of a golf ball, with 1/8-inch-diameter perforations. This device, used with a high-pressure water pump, enables the driver to wash out hard-to-reach areas of the fins.John Eldred of Smiths Concrete says they buy the spherical tip from the UK office of a Finnish firm called Toftejorg. The UK address is Sanderum House, Oakley Road, Chinnor, Oxfordshire 0X9 4TW.