I don't think it's a soap formed, but saponification is not the only chemical reaction that allows oils to solidify. Bile is a mixture of lye, salts, cholesterol, (green and other) pigments, enzymes etcetcetc. The oliveoil is premixed with juice so it forms an acidic emulsion even before hitting the digestive track. So while I agree that "the stones are just soap" is probably a non-argument, neither can the fact that that single argument is invalid be used as a argument to state that the stones are real (sorry for the twist in logic).
I think the truth is somewhere down the middle, as always: real gallstones (as in medical literature) are solid, calcified, mainly composed of the bilesalts. They sink in the toilet, do not dissolve in water nor float. Small, fresh formed gallstones are brittle, dry, but not the fatty green blobs you passed the most of. Yet, I've found such green globules in the canals of a calfsliver I prepared for my cats once, so I do think they can originate from the liver, if not from the gallbladder. I still feel like the bulk of the passed "stones" is gelled up olive oil (that has been premixed with the grapefruitjuice), mixed with stomach acid, bile and passed though the digestive system to form green globules. Otherwise, you should have fatty stool afterwards, with the oil just floating on top. Since that doesn't happen, and you dont gain weight over night which would indicate that the fat is digested, the olive oil is somewhere in those "stones".
As in regards to the black stones: Dark brown to black are pigments that are in (often older) bile, so it can be the same as the green stones, a signal that the bileduct emptied itself completely. It might be a few real gallstones, especially if the black ones are relatively small ones. Black is also a colour that can come from the liver, or it might indicate anything from a stomach ulcer to a bleeding in the smaller intestine. Bleeding in the large intestine would show as red. It could also be stuck old food (especially if you eat meat) that came lose from the intestinal lining due to the flush.
As to the: "when people empty the bladder and livers, no more stones pass" I've done it a few times in succession myself and know a load of fellowstudents who did it themselves. Some really healthy rawveganfellows. Yet they all continue to create stones, one time more than the other. I have yet to hear of one person who stops producing the green fatty floaty stones. It's part of the myth that everyone repeats, but no-one checks. That's part of the danger, people just follow the advise of others without educating themselves on the subject. If I altered the recipe and added a tad of ratpoison "to kill intestinal parasites" and posted it online, I wonder how many people would just be selfdosing themselves with poison.