John,
I had a couple smaller stone dumpings, once even NONE but then I got a LOT <like 200...hard to count because of the line you have to draw between stones and gravel.> I think it's a matter of timing, a little bit of luck, and maybe what you ate the day before.. Sometimes the bladder is fuller with bile than others, sometimes less full.
I recommend you do another next month, on the theory there were some that you might have loosened that will give way the next time.
And follow my advice and NOT mix the grapefruit with the epsom salts...you will get a better bile discharge. In fact, go a day without any acidic or fatty foods...the longer the better.
I was all set to do one last month but then got screwed up with a dental emergency and my plans went up in smoke

. Next week for sure if the store has some good unpasteurized apple juice. Liver/GB seem kind of "full" feeling.
MAC,
It strikes me as logical to assume that once the GB is emptied there will be a corresponding push by the liver to refill it. I think that might stimulate release of some stones from the hepatic ducts? And then THEY'D wind up in the gall bladder for the next flush. Hard to know for sure though since cholesterol stones are invisible to X-ray.
The medical profession is a hard sell on this even when confronted with the evidence of Tbsps. of bright green stones in abundance that are collected from...well, COLLECTED!
After all, they make ZERO dollars when we do a flush and many many thousands when we have our gall bladders surgically removed.
What's the old saying very apt in politics? "It's hard to make somebody SEE something when their salary depends on NOT SEEING it."