They work well in a wet/dry application just like bioballs do. They have less surface area so they wont plug up easily, but they make up for that with the large quantitys that you can use. When they are submerged there is less oxygen available, so there is less growth. The ceramic media has a TON of surface area due to the porous surface, so there is more area for it to grow on. if I could fill a wet/dry with ceramic media I would, but it's too expensive lol...
(besides that, it would plug up)