Just filled it with water for few seconds, left to dry for a few minutes and it was opened & ready to go. As a total beginner I was able to produce clear sound immediately (I have some experience with sax previously, not a double reed but that might helped a bit)
It's a quality mouthpiece great for beginners BUT the only con is the price. It's ridiculously expensive, that's why I'll give it 4 stars overall.