Hi Heather! I like the idea of the wheatgrass. If you google that remedy it does have some merit. Like I said, for me, it worked. Ad that stone had bothered me for a total of three months.
Getting to your question, yes, they do use sonic waves to break up stones that are too large to pass. It can prevent surgery in many cases.
What causes them are still hard to determine, but they can be analyzed so if you know which type you have you can avoid certain foods. Oxylate stones means you have to avoid spinach and other veggies. Calcium oxylate stones require you to stay away from milk and other dairy. If you have too many oxylates in your system they will crystallize and cause stones. Most pass and you never know. If they are too large they can stay in the kidney and pieces break off and then cause pain. You can get blood in the urine from a stone when it's moving. I've had it to where I thought I was making Merlot. It is scary, but as long as it is nothing else it is more frightening than worrisome. At least in most people.
I don't think you should worry about cutting out detain foods in order to prevent them unless you have had stones and caught one to have it analyzed. If you haven't had kidney stones don't worry then. If you do get one it will make itself known. Then you can deal with it.
I will say that keeping hydrated lessens the chance of getting stones in the first place. It also helps with things like gout, which is almost the same thing but uric acid crystals settles in your joints and it can give you a lot of joint pain.
Sorry I've given you more info than you wanted, but at least you now have a basic understanding. If you ever get one or think you are getting an attack, see the doctor or go to the ER. Once the pain starts it only gets worse. It can last a short time or days and weeks.