So a few weekends ago I made my way down to the New Jersey shore. Specifically the Jetty off of Barnegat lighthouse on Long Beach Island.
I was running a bit late so my exposures were a bit fast for trying this technique. I tried it anyway and set the ISO to its lowest setting on the D800. (Low1) and stopped the 24-70 f2.8 lens down and still was only able to get the time down to a second. Doesn't give much time to use the technique... Here was my best attempt.
D800 24-70 f2.8@ 24mm&F22. 1 second exposure total. Black card momentarily held at horizon and pulled away quickly after shutter opened. No real measures time involved for black card. Metered on rocks.

I have never heard of this technique, and I do like the image.