Yeah, after giving it some thought, clearly the change in the density of the emulsion is not per se evidence that the aforementioned approach is in any way a good idea if I want to get an image.
Holmburgers, thanks for the tip. I've just sent him an email asking for his input.
My current theory is that a dilute analogue of the original chemistry could be mixed, and the exposed film then loaded onto reels and souped in it, in a tank. I've done some hand-processing of Super-8, and still have the dingus that I built to wind the film onto.
An aside: When you hold the film stock up to a light and look through it, there's the most beautiful prismatic effect as the different layers separate the image into cyan, magenta, and yellow.