I went to school in a rural school system, whose audio visual department was a couple generations out of date, as is common. I remember we were shown an X Ray film from the 1950's in which a profile of a human being is shown chewing and swallowing food. The skull chews and you see gray globs of foodstuffs oozing down the esophagus. I'm tantalized at the thought of this retrotechnology being applied to multiple cum swallowing scenes. I imagine a Greg Dark-like strobe effect in whic ordinary video of the woman receiving cumloads mouth agape is alternated with X Ray footage of her skull, unhinged as if crying out in terror, and the oozing gray semen flowing down her esophagus. It would be a marvel.
Perhaps an X Ray 'Gag Factor' would also be a swell idea.
And how about this: Have the woman come back when she has her next bowel movement after a multiple cumload swallowing scene. Wouldn't you be interested to see what her shit looks like?