I posted this in another eflow topic, I'm just copying + pasting...
<i>You have to at least rinse the nebulizer head (metal part) off with water after each treatment. There are microscopic holes in this if they close up then the treatment is not going to be as effective and will take longer. At the end of each day you should boil everything but the head in water and soak the head with isopropyl alcohol. After soaking the head with the alcohol you should rinse the alcohol off in the now non-boiling water that has the rest of your nebulizer parts. After that take the parts out of the water and let them air dry.
At least that's what my boyfriend did, he had the eflow for 2 months (using the same head for the entire time) for a study and never had a problem, and the treatments from the start of the study to the end only took between 3 - 5 minutes.</i>