I didn’t think I’d like the EarGear things, but they do a good job keeping dust and water off the aids when working outside.
Downside is they don’t seem to be very well-made. The spandex covering on one of my elastic tethers lasted one day before it unravelled. They replaced it promptly, though.
[*Addendum: VAC
also provided me with a pair of Oticon brand tethers. No sock - just heavy duty silicone O-rings attached to sturdy tethers and a clip. I like it because it’s simple, but, I have to give EarGears the nod when it comes to keeping dust and debris out of the microphones.]