Oh okay, I was thinking of running the line threw the ball and coming out and down a few times to hold the moss but it may be easier your way.
Actually I think you're idea is a great one! I would probably use a large eye needle and thread the fishing line through it and maybe poke it through the styrofoam ball at the half way point....that would work perfect. Sounds like it might even be easier. I think I'll try that idea next time