That’s a tough one. I went online and looked briefly and it seems like you’re doing what they advise. You could call the company though. I think the issues are very similar to using a humidifier. There’s a reservoir and it’s just difficult to sterilize all the nooks and crannies. However, like you said, it’s something you need to use so that seems to take precedence over everything else. Sometimes we just have to say to ourselves I’m doing the best I can.