I've done Dr. Clark's flushes three times- (last one last week)
All I took were the olive oil, Epsom Salts , one grapefruit and two Black-Walnut capsules (emptied into the grapefruit/olive oil-- to kill any possible parasite larvea hiding in the liver)
I didnt take any extra stone softening things at all.
My first flush produced small stones, my second flush produced older , duller green larger stones- and so did my third flush.
The larger ones were the size of lima beans. I didnt check to see if they were hard or soft, though.