The way my dad removes moisture from his hearing aids at home without the use of any other products is to use some rice.
Take a plastic Ziploc bag and add some rice to the Ziploc bag and then place the hearing aids in the bag of rice and let the rice cover the hearing aids for a few hour or overnight.
The rice will naturally draw out moisture from the hearing aids without harming them.
I've also used rice to get moisture out of my cellphone before when it got moisture in it and wouldn't turn on so the rice does work good for removing moisture from cellphones, hearing aids and other electronics.
You can also buy some commercially available moisture remover for hearing aids but the rice works just fine and is usually cheaper.
Or you can get moisture or waterproof hearing aids although those cost more than regular hearing aids.