small nut big problem

[Scottem]

During the installation of a dual quad set up, a small 1/4" nut may have fallen into one of the four front cyclinders.

The intake has been removed and I'm able to look around the valves and there appears to be nothing. Put a magnet down there and still nothing. I've searched all around the engine, engine bay and under the car. My conclusion is that the nut may have fallen into a combustion chamber and is probably sitting on top of a piston.

Is there a special tool which can be used to find and retrieve the nut? Go through the spark plug hole?