Found some Ivory Mystery Snails yesterday at a pet store. I didn't purchase them because they had a little green algae on their shells, other than that they appeared active and healthy. Would like to go back and get them IF there is a way to clean it off. I was thinking of maybe trying to clean it with a toothbrush? Can this be done? I'd like to have them but don't like the unsightly algae on them. I am picky and expect them to look nice.