Ok, I followed you as far as calculating the 90.8 cc of stones. Assuming the stones are spherical is a reasonable simplifying assumption, but probably estimates a little high. Extrapolating from there to 125cc total volume? Probably not outrageously inaccurate.
You lost me on the conversion to cubic inches. 2.54 cm = 1 inch, so the conversion is 125/(2.54^3) = 7.6 cubic inches. The largest single flush, the second one, calculates to 44cc or 2.7 cu in.
Given that this volume is the result of 3 flushes, the stones wouldn't all have to be contained in the gallbladder at the same time, but the gallbladder may not empty completely in one flush, either.
A quick internet search turned up figures for gallbladder volumes ranging from about 25-35cc for normal adults, to as high as 65cc for some obese people. 44cc is within this range.
I'm not saying flushing does or does not work. The jury is still out on that point, as far as I'm concerned. I just hate to see math abused as badly as you have done here.