In pondering all this, I'm really starting to lean heavily toward the problem being mold in the warm humidifier chamber. I say "chamber", because its not limited to the reservoir itself (most of which remains predominately submerged and incapable of fostering growth of much of anything). In my case, the DreamStation has a [fortunately removable] gasket between the reservoir and the outlet to the tubing. I think its made of silicone, or similar, but it does seem like it would be more porous for mold to cling to and reproduce than the hard plastic reservoir itself. That in mind, I think I'll begin cleaning those, and occasionally the hose, with vinegar as suggested by Sleep Enthusast Sierra, above. I've also read that mixing vinegar with peroxide forms a potent cleaning solution. I've been using an antibacterial cleaner (lots and lots of rinsing of course), and its totally illogical if the problem is mold instead of bacteria in there.
Where, exactly, are the bacteria, mold, and other irritants, accumulating in a CPAP machine? I'm tired of fastidiously cleaning everything imaginable in an attempt to minimize my sinus symptoms without any rational explanation of the real problem. There is a considerable body of cleaning instructions available online, much falling into what I call "elephant repellant" [Living in Pennsylvania, seeing an elephant will not be the result of any particular deodorant or cologne, much as one might have noticed a correlation.]
First, its illogical to presume the pathogens are entering the system during the body's exhalation of air; its a positive pressure system wherein air is constantly flowing from the machine into the device on one's face. In my opinion, the pressure is actually keeping the system clean from that end of the tubing, I understand that my nostril cushions will accumulate pathogens already in my sinuses or living on my nostrils themselves, but surely that is not a major source of the sinus infections and other symptomologies frequently discussed. Our bodies are already countering pathogens in/on our own bodies. Yes, washing the mask or nostril cushions every few days makes perfect sense.
Next, in some science advanced by Fisher and Paykel Healthcare, they explain why water vapor from a heated humidifier is way too small to function as a delivery system for bacteria and other pathogens that are nearly an order of magnitude larger than the vapor particles. Further, the heat in the humidification unit is actually killing some germs. Quite simply, it seems improbable that bacteria in the humidifier are being blown into the body in any significant quantity. They go on to say that a [clean, obviously] reservoir of distilled water is not a suitable medium for bacterial growth. I would temper this by admitting that a warm moist environment will cultivate mold spores that pass through the filter, but how long will it take for the mold culture to be producing more spores than were already in the ambient air? Will a "regular" vinegar/water soak even kill mold? Is it possible that mold spores are the more probable cause of people's sinus infections?
If the primary origin of the bacteria and mold is the air intake of the machine itself, doesn't that make the innards of the machine, where one cannot effectively clean, perhaps more "dirty" than any other part of the machine?
I would really like to hear some scientific discussion of pathogens in CPAP systems, leading to reasonable cleaning practices. Thanks in advance to any/all who attempt to add clarity to this topic.