I can think of a million reasons not to trust Ken Rockwell. He's just telling lies right there...
I know a photographer who completely destroyed her new D2X by wiping it carefully with a swab that accidentally had picked up a microscopic bit of dirt.
The filter in front of the sensor (you can't actually touch the sensor, there is always something in front of it) is basically a piece of glass. I'd like to see Ken try and "destroy" a piece of glass using only a swab and a "microscopic bit of dirt". Good luck Ken!

You'll have a hard time damaging the sensor. It's not as fragile as people tend to think. You'll still want to be very carefull with it, but Ken just doesn't know what he's talking about. Seems to be a common theme along his website...