Need help with fixing figure

Posted in Custom Workstation

Hi, I just bought a Phantom action figure by Cast-A-Way toys. So it’s like a mego style figures. When I found him his hands had yellowed a bit. I tried fixing it using the Hydrogen Peroxide method. I also used a method I found online using Salon Care 40. Neither worked and in fact spread the yellowing. I need help figuring out why. The hands were flexible plastic. Almost rubbery. Could this be partly responsible?