I made Cornell Chicken last night. It reminded me exactly of firehouse and church chicken BBQs of my youth in New York State.
I stuck exactly to the recipe from the "perfessor" that was cited at the top of the thread, and didn't deviate a millimeter. I decided on a short marinade of about an hour because the cider is so overpowering. For poultry seasoning, I used a brand called McCormick's, very common. I used a regular egg, not a large egg, and emulsified the egg and oil first in a blender before adding the cider and then the seasonings, pulsing things together with frequent bursts as they went into the glass. It makes plenty.
I frequently turned the chicken with a pair of tongs as it was grilling over a very hot fire, slathering on in the abundant Cornell recipe sauce every time it turned. I made an entire chicken that was cut lengthwise into two halves deboned to a certain extent so the halves would lie flat. The recipe would have accommodated another chicken easily.
In a word: Delicious! Rather than a sweet taste such as BBQ chicken, there is a slight cidery, salty tang to it. The chicken came out very juicy even though it went through some hellish heat, confirming that the recipe seals in the juices.
I'd highly recommend using a meat thermometer so you can gauge the right time for "doneness." Also, if you use chicken halves as I did, beware that at the end of the process the halves tend to tear "in half" where breast meets leg as it gets tender-done.
Great grilling, everyone. Thanks for the recipe!