I use Dimension3D's Delete script. It'll delet everything you tell it to (may it be Cameras, Lights, Props ... etc .. ) in a blink of an eye. Also very easy to use and very reliable, as Snarly's script is/Snaly's scripts are.

If interested, it is included in this free bundle of scripts here:

http://d3d.sesseler.de/index.php?software=poserpython&product=12_pythons