hey all, I just bought this, and Im not overly sure how it should be set up. Can anyone help me with it?

Dymax 107 Diffuser

Should it be filled with water? This seems unlikely as the only way I can think of to fill it is to blow water in it with a bit of tubing. If not, how (as it states) is the spiral supposed to keep the gas in contact with the water longer? Also, there appears to be a small hole in the base of the spiral, which, when filled, the gas just comes out of. Any ideas? Im mildly confused.

Thanks