I clean my hose whenever I remember to, which averages about every 3 months. No, I'm not kidding. Sometimes 4 months. It's not a sterile environment anyway, nor is is meant to be. After all, it intakes and passes through it the very same air you'd breathe in your bedroom without the machine. Yes it has a filter, and some use HEPA filters, but I just use the regular kind. I wash my nasal mask once a week.

My routine, as a cheapskate, is to rinse it with soapy warm water (good ol' Dawn does a great job at this, cleaning fine optical surfaces, cleaning dogs who need a bath...it's perfect for this). Part-fill, and then lift each end of the hose alternately to run the solution back and forth. Drain, rinse, and then comes Step Two: I keep a resealable bottle under my sink with a solution of potassium or sodium metabisulphite. It's a white powder sold widely in DIY wine and beer stores as a sterilizing agent. Cheap, like borscht. A pouch that will last you three years or more is about $5. To half a liter of the water you add a tsp or two of the metabisulphite powder and dissolve it by swirling and tilting the closed jar/bottle. I do this days ahead and let the solution 'perk' to full potency, which you'll soon detect if you put your nose close to the open vessel and take a whiff. Great for clearing the sinuses! I add some of that to the tube and repeat the lifting of each end alternately. Let the solution contact the connectors on each end...won't hurt them at all. After 20 seconds, drain down the tub drain and rinse well. Well. Then drape the hose and restore it to the machine later in the day.

In case it's news to you, ozone is like a powerful oxidative component in food or in chemicals. It attacks organic material aggressively, and is why you have to be careful running those small plug-in ozonators to keep unpleasant odors at bay in musty basements; the ozone will attack wiring insulation, and plastics...oh and the plastics on your CPAP machine as well....all of them.