We use each neb cup (Pari LC) just once per day for our son and keep about 5 or 6 of them on hand. For washing we soak them in soapy water with bleach. I rinse them with tap water, but it sounds like I'll want to change to boiled water. After rinsing, they immediately go into a steam sterilizer in the microwave for 4 minutes. After that we shake out the water drops. During the dry season they air dry within a few minutes. During the humid season they have to be wiped out with a papertowel. I stick with the microwave because I read a study done for hospital lab purposes that tested a bunch of sterilizing methods and found that Psuedomonas A. could only survive microwaving for about a minute or so.