Thank you! I don't think those can filter water. They are pretty dry and stuck to the surface. Mosses are more "fluffy" and can hold a lot of water. I think I saw somewhere that if extreme situations you can squeeze the water our of a moss and drink it. Probably there is lots of tiny organisms in that water - but you will survive ;)
Not sure about the properties of those and if they can be used in a medical way... I simply love how they look :)