There are a couple of herbs with anti-spasmodic properties: dill, fennel, caraway seed, cumin, peppermint in lesser degree. They are all relatives, except peppermint. When I feel pain coming in I take 1/3 of tea spoon of caraway seeds and chew them, then swallow. It helps to take the spasms off and does not interfere with digestion. The ACV works also, but the mechanics are different, it reduces need for bile, so it does not try to get out of the gallbladder, so no pain, but you need bile to digest fats and proteins.
There is an over the counter medication in Europe, called No-Shpa. It is widely used to alleviate gallstone attacks and spasms. I do not know if it exists here, the active ingredient is dropaverine.
I use ACV with meats, just pour over a piece. And take some caraway seeds in the end of the meal. Also, add caraway seeds in soups and other dishes.
Just my 5c, :)