Jenny, you "flush" your gallbladder every time you eat a plate of French fries. Seriously, a high-fat meal causes the gallbladder to contract and empty a significant proportion of its contents.
If you have gallstones, trying to make the gallbladder contract harder and empty further is more likely to precipitate problems, because symptoms are caused when the stones get stuck in the neck of the gallbladder as it tries to empty itself of bile. That's why many people with gallstones get symptoms an hour or so after a meal, and those symptoms resolve several hours later, when the gallbladder relaxes.
There are medications that are successful to some degree in dissolving gallstones. The problem is that they have significant side effects (cramping and diarrhea, mostly), and that once their use is discontinued, the gallstones are very likely to recur. They're really not used for those reasons.
If you have symptomatic gallstones, by far and away the best, quickest and safest treatment is gallbladder removal. I watched two young men (in their 30's) die of gallstone pancreatitis during my residency. The illnesses were prolonged and miserable, and I don't ever want to see anybody else go through that. Now that gallbladder removal is done laparoscopically, the recovery is quick and relatively painless, and absent serious contraindications to general anesthesia, there really is no reason to avoid having it done.