Nope, not yet - and I started this thread. Yes, it's annoying!
I actually rooted my S2 since I was going to move to the S4. I figured that if I screwed it up, no big loss. Want to move some tones and such over to see if I could change the water sound. Since then I have yet to figure out how to find those supposed hidden tones on my now rooted S2. And if I do, I still have no idea if one can change the damn water sound.
Far as I know, it can only be shut off, but what do I know. Oh, and yes, feedback is good.
And we await an answer...