I intend to accept your challenge. I'll buy some tomorrow, and try to make a crappy video.
To recap (and ensure I understand The Rules correctly) - The stated and challenged quantity of Jaffa Cakes should be inserted entirely into the mouth of the acceptee with the Cakes remaining in a Whole state. Do lips have to be able to close at this point?
Then, once the above rule (and question) is satisfied, the acceptee must consume the cakes without any outside assistance (including hands or other people/objects), until most traces of cake are swallowed or a choking/breathing incident occurs. Small amounts of Cake remaining within the teeth or on the walls of the mouth/gums is allowed.
I assume that the video must be a single 'take', and show a before and after of the mouth (but not TOO close up, because young innocent people might be distressed at images of mandibles both before, during and after a Jaffa Cake session).