Well, the Green M.U.S.C.L.E. that I had left in the pool lightened up very nicely, but not as much as I had hoped. I have come to believe that it is sunlight that lightens M.U.S.C.L.E.'s better than a bleaching agent like chlorine in a pool.
Here's why I think so:
I got frusterated with the fact that the figure was not lightening fast enough, so I put him in a cup with a chlorine tablet for a super chlorinated solution for faster bleaching. It ended up effing up the figure's plastic a bit. So as an experiment, I cut him in half.
Why in half, you ask? So I could see how far through the figure the bleaching went. I noticed a layered effect. The figure was a very light green all the way through, which means the sunlight penetrated the whole M.U.S.C.L.E. and bleached evenly throughout it. But the surface layer, it's "skin" you could say, was white from the chlorine only. This means that the chlorine water cannot penetrate the entire M.U.S.C.L.E. I figured this would happen, since plastic is not very absorbant.
So if you want to bleah a M.U.S.C.L.E. figure completely, you'll have to leave it in UV light for a long time. I am in the process of leaving another M.U.S.C.L.E. figure on my roof in the Arizona sun for as long as it takes, becasue I cut up the "TEST" subject.
So those are the results of my Bleaching Experiment. Failure the first time, but most likely success in sunlight only the next. I want that "Completely White" look. I hope it works.
I also believe that bleaching the neon figures, green and orange, would be the fastest and easiest way to go. They are light already and would probably lighten up much faster in the sun.