A couple of things...

First, treat it like a diffuser stone and soak it for a while before using it.

Second, I can't believe the coils are to improve contact with the water - it's for aesthetics and to act as a bubble counter. Over time water should start to make its way past the disk into the diffuser. The hole at the base of the spiral will allow water in with the bubbles so you can see them travel up the spiral.