I tried to reproduce what's on the Prayer Man site while listening to the creepy MK Ultra podcast, and this is what I found.
First of all, I don't believe there was any attempt at deception, they just worked the image until they were happy with it. Image processing is more an art than anything.
And if you want to try it at home:
1. Find a suitable Darnell clip to start with, and capture the "scene".
2. Greyscale the image to make it black and white.
3. Increase the color depth to 16 million (24 bit).
4. Play with the color channel brightness curves.
5. Adjust brightness and contrast.
6. Keep fiddling until you like the result.
I got close to what's on the PM site. This is why I called it "heavily filtered", there were many steps involved. Unless the person who did it took meticulous notes, you may not be able to reproduce it.