Dust inside a sealed housing
 

One of my favourite small handheld cams, a Sony 96Gb PJ790 HD has managed to get a dust spot or something inside the lens housing which is sealed, a replacement of the housing would probably be more than the cost of the camera, so that's not a runner!

Some things I've tried already;
Held the cam near a piezo switch until the arc was touching the camera body in an effort to charge the particle and perhaps attract it to the side of the housing, but that didn't work.

Tried to create an electrical charge to again attract the particle to the side by dragging along a nylon carpet.

Applied some heat to the glass element in the hope that the dust spot might separate from the glass and float to the side of the housing, again this had no effect.

Does anybody know of any tricks to disengage the spot from the glass element?