F20 Quietair elbow question, help!

[RoboLobo]

Hi everyone. I have recently switch over from the Simplus to the Resmed F20 Airtouch FFM, which includes their QuietAir Elbow. As has been noted elsewhere, it is freakishly quiet, a real marvel of engineering. However, after about 2 weeks of using it, I can see what appears to be tiny white strands of fiber of some sort underneath the hard plastic piece that covers the vent holes. What is that all about? I *think* it might be strands of fiber from the Padacheek mask liner I have used a few times with the mask, although that liner is blue in color and not white and I am definitely not seeing blue fibers. It's not a product feature, is it? That would be crazy. Maybe my lungs are falling apart and I am exhaling strands of lung fiber? That's even crazier (and dumb). The problem is that said fibers don't seem it want to rinse out of there very well, and as far as I can see that hard plastic piece is not removable, and it's too tight for a toothbrush. Ideas, anyone? Thanks!

[JXG]

There is a felt disc under that plastic cover, so over time it would be reasonable to see some of the fibers from the felt peaking out.