Hi Russ,
If you are not suffering and urgently have to flush, why dont you give gold coin grass a try. Its suppossed to soften and break down the stones. Im on it now in tea form but am waiting to do my next flush. I dont think the size of your duct is the big issue as the gallblader is a very powerfull little organ as anyone whos had a bad attack knows. Every time I do a flush, I try to look on the bright side, if the worst were to happen at least I wouldnt have to go on a waiting list for surgery. (he he)
Susie C