I just did #15 using this method and I definitely got out some stones, which was more than the last few flushes. But I had also just finished a bowel/parasite cleanse and wanted to do this flush just prior to my monthly cycle.
What was different about this flush is that I did not get thoroughly cleaned out just prior to, so there was a lot of stuff mixed together, but I could definitely detect some garbanzo and lentil sized stones, lots and lots of dark greenish black bile. I continued to pass this for a day or two. I also saw dark green floating oil spots, so these were distint from the stones themselves. What was also very different is that I released so much concentrated bile that it did a number on my hemorrhoids - worse than any other previous flush.
I ultimately consumed 1 1/3 cups of olive oil in apple juice with apple cider vinegar over a period of about 30 hours. That is a lot of oil. No epsoms were used - this particular flush does not call for them.
I was told that my liver was clean but that my common bile duct was slow/sluggish, so I guess that is where all the backed up bile came from. And the odor was off the face of the planet.
Bragg recommends this flush twice yearly.