Sterilized these by boiling in water, product did fine. Water remained in the bulb, could not get it out. Squeezed it multiple times, let it dry out for a few days and there was still water trapped inside the bulb. Figured it wouldn’t be worth it because if water got in, it would eventually come out. Didn’t wanna it to grow mold or other bacteria and have baby chew on it. Needless to say, I threw them out. Better safe than sorry. Tomme Tippe (I think that’s how you spell the brand) has great pacSee full review