Sensor clean again.
Actually I tried lots of vibratory activity first, which managed to move one of the bits to a different location but not off; you have to take into account that the mass of the particles is extremely small compared to their affinity for surfaces. The combination of vibrating the particles free of the surface while air moves them away is the principle that Nikon uses - or so I gather.
I was somewhat concerned about airflow damage but there really isn't much in there that wouldn't take some air velocity. It's a matter of what is considered more than 'some'. I have my brother's dust infested G9 to do next so I'll see if it dies or comes up clean.
I'm glad you were able to clean the sensor, though I believe it was the result of all the vibrations due to your cleaning activities that did the trick. Any time you get air flowing through a camera you risk replacing one problem with another.