Hi Simon,
never worked with this before and not all servers will support this. You would also have to contact that guy because he wants everyone to contact him if they want to use this script.
More importantly however, I think the problem with WB is that for each image a different value will work. So you optimize the script for one image and it applies it to a different one and makes it even worse. If the brightness of the image changes during the day, then this is going to be a problem. If you make it darker, then it will be useful for bright images, but make darker images even darker and vice versa.