These molds have brillammment passed their first test. I've lightly oiled since it was first used. (The small leaflet accompanying the advised.) The result was spotless. The mussels are really flexible which offers two advantages: easy release and cleanup too. However, you must have this "silicone mold strip" on a rigid plate (I used my pizza pan.) Before pouring the batter. And hop in the oven! I regret not being able to put pictures!