What you are looking for is water resistant speakers. Outdoor Speaker Depot (OSD) sells a number of models which are designed for 'wet use' locations. In-ceiling is what I have used in shower spaces and out on decks. They work fine and sound okay. Nothing special.
The other thing I've done is mounted speakers UNDER decks. This way you can get some pretty nice speakers that cover a more traditionally exposed outdoor deck with decent sound from every direction.
So, yes, you have some options here, and yes I've done it a few different ways. Not sure there is a in-wall version from OSD, but be very aware that you want to keep moisture away from any in-wall setup to prevent water from getting into the home.