[Leica] M Sensor Cleaning: people's current favorite devices and supplies and techniques?

[jbmmllug at jbm.org (Jeff Moore)]

During recent fussing-about with a photo containing a vast expanse of
sky, shot with the lens stopped down reasonably far...  I found myself
no longer able to blissfully ignore whatever crap has collected on the
sensor of the newish M.

I'm really bad about getting around to sensor cleaning, but I think
I'm going to have to bite the bullet.  This camera seems particularly
fond of getting stuff on its sensor, possibly partly because of the
time it spends with the shutter open during live-view interludes.

So anyway: do the experienced sensor-cleaners in the LUG have current
favorite tools and supplies to use for this chore?  I remember years
back there was talk of butterflies and I dunno what-all-else.

What are people feeling comfortable with these days, for sensor safety
and efficacy?  Are there distinct dry and wet approaches?

So far what I've come up with searching the LUG is references to
Eclipse fluid, and looking at that vendor's info, it seems that the
"Type 3" swab are the right size for the M240's full-frame sensor.

Anything to add or change, any particular gotchas to warn of?

Thanks in advance...

-Jeff