I've had my gear iconx (2018) for about 7 months now. They've been sent away twice for repairs and on both occasions the technician removed the dust proof membrane and the mesh. The result is that I now have no replacements left myself and the audio has dipped to the low level it gets to when the mesh has run its course.
I clean them on a bi-weekly basis, but there's obviously a pretty finite shelf-life for it. I do use them heavily (cycling / gym); but I can't find any more replacements for the mesh anywhere. At all.