pert:
That picture is quite strange:
Yes, it's reminiscent of what's in your toilet tank.
pert:
Are you suggesting using the ball valve to pinch the tubing off, that's an interesting idea! Or are you merely suggesting that it should be used for its intended purpose?
The latter. Just the first thing that popped into my head. Actually, if only noncorrosives are used, one like that for your refrigerator icemaker would do the job too.