I've seen people use the high-strength hydrogen peroxide the kind you can get at the Cosmetic or hair supply store. You have to spread it all over it and then let it sit in the Sun but this is the first time doing anything like this for me so I just decided to give it a shot with the Clorox Clean-Up and it seems to have gotten it pretty clean it's still a little tinge of yellow in it but it's a lot better than what it was. Let's just say it work for me I don't know if it's going to work in all situations. I definitely would not go using full strength bleach on it as it could maybe. melt the plastic but I'm not sure.