Great find.

My only concern is how do you know the o-ring is (and more important, stays!) still in place when you put the two halves together?

Soon as the o-ring slides out of the place the pupose is defeated or even worse, the o-ring is in the way of the inlet.

Using glue is something i'm reluctant to use as loose particles of the glue could get into the water.

How did you guys overcome this?