Vortex tube should have a supersonic nozzle for efficiency; a simple drilled hole will not allow supersonic flow, right? Answered
Scientific American had an article on supersonic nozzles in Amateur Scientist. The nozzle needs to first narrow and then widen, so that maximum velocity is reached by the expanding air.
The Hilsch tube seems to be very primitive because of details like the primitive nozzle. Perhaps, the Hilsch tube was designed to have too much friction. Perhaps, the tube was built to be sure it was inefficient and not very useful. The tube can only violate the Second Law if it is built with a minimum of friction losses.