Because blowing your nose is not enough. (Although I think I will stick with it instead of using this medieval torture device)
Here’s how the Nori works:
Place half a tea spoon full of sea salt into the Nori and fill the container with water. While leaning over a sink, tilt your head sideways and slightly insert the spout (outlet) into one nostril. Slowly lift the Nori so the salt water flows into the nostril. Important: Your mouth must stay open! The salt water will flow through the nasal passage and come out of the other nostril.