Increasing citric acid intake does seem to be helpful, at least for calcium oxalate stones (one of the more command kinds).

I've had more than a few stones over the past couple decades, and when I finally got myself in to see a urologist, that was one of her primary recommendations.

That, along with some other treatment, seems to have helped considerably (only one non-trivial stone in the last ~12mo & the few others were barely noticeable).