Don’t take my word for this, so take this as just a guess, and check yourself before trying it.
It is very likely these are nothing but silica gel, which can be dried in the oven or microwave. It will likely change color again when dry.
Phonak sells them as consumables to: “Create additional business for your clinic with refills”, as stated on their website.
Wikipedia says to dry at 250 °F for 1–2 hours.
I may be wrong, so check this yourself before trying it. They aren’t terribly expensive to just buy new ones.