The Pixie Cup Sterilizing Container will fit most silicone menstrual cups. INSTRUCTIONS: Unfold the sanitizing container and set on countertop. Place menstrual cup in the sanitizing container and add Pixie Cup Wash or any organic silicone-safe soap. Boil water separately and pour over menstrual cup. Let soak for a minimum of 5 minutes. Remove and rinse your newly sanitized menstrual cup. Our sanitizing container is completely microwave safe.