This is really quite freaky. Ive only just stumbled across this thread...........honest I have, and
Ive just come back from the workshop where I have been drilling a block in a very similar fashion to the ones from Max and Volenti.
Mine has a copper middle section with a 20mm circle of 2mm holes (37 in total) acting as jets directing flow directly into dimples in a base section. The water then flows away to the sides and out.
God knows if it will work, since the appliance of science has been distinctly lacking in the design, but hey, it costs nothing to try
