The magnesium citrate is a laxative. I wouldn't take anymore than is recommended on the bottle. Malic acid is something found in apples that helps soften the stones. I was taking 800 mg per day before my first flush and nothing happened so I read in an old post to take 2400mg/day, and I have been, and I got lots of stones on my second flush. If you're getting lots of malic acid directly from apples, though, maybe you don't need to supplement as much.
The mc just might make that cyst on your kidney disappear. From what I've read about it, that's what it does. I did a 10 day mc in January, and am planning a longer one very soon, maybe even wednesday the 1st of March. I wish I would have flushed my liver before my last one, so pat yourself on the back for doing it right!
best wishes!
Sem