Thank you all for your helpful answers.
Upon closer inspection, there are still many visible patterns on the sensor after a polonged additional session with Sensor clean.
I have decided to take my D3 to the Nikon service Center in Shinjuku this morning...
Nice - you can take the subway to Shinjuku and just get it done. Here in Toronto it's a car drive on one of the most congested and dangerous roads in North America forth and back, then a day or two later forth and back again because Canon has no while-u-wait sensor cleaning service and their service facility is hugely out of the way for anyone living in Toronto proper. Getting your sensor cleaned here exemplies the joint efficiencies of Canon service and Ontario infrastructure, but frankly, all that said, probably the safest way to get the sensor cleaned if its owner survives the traffic.