Dunno about all the rest, but for me, personally, Kidney stones are the height of pain I have ever experienced. Luckily, all have passed without the need of surgery or stents or anything. As to the OP, I passed am 8mm stone, with flowmax, and percocet. I imagine a 9mm is passable as well, however, as with anything body related, everyones body is different, so your ureter could be smaller in diameter, or larger, etc.. (no jokes here please fromt he peanut gallery lol)
As has been said, WATER. LOTS OF WATER, and take the pain meds as prescribed, meaning, if it says every 6, take it every 6.. Pain is much easier to control than eliminate, which means, that, its harder to get rid of pain that is there, than it is to maintain pain relief. That being said, get off the pain meds ASAP after passing "the beast" or you can become addicted... and though I have never experienced it, I saw a friend go through opiate withdrawl (he got hooked on oxy after a motorcycle wreck) and it is not pleasant....
Best of luck to you sir...