Getting yellow plastic bubbles clear again?

[BabyTaffeta]

Has anyone ever heard of a method to get a yellowed plastic bubble or front from a MIB pony to get clear again without destroying the original Packaging? I have no problem with sunfaded cardbacks or card boxes with MIBs but the yellowing is a bit odd 
Any ideas?

[BlackCurtains]

I've often wondered if Retr0Brite would work on plastic bubbles. It's for ABS plastic so maybe not.

The only thing I know would work is using a peroxide paste and then letting it sit in the sun, but that would harm the pony inside and the card.

[BabyTaffeta]

I've often wondered if Retr0Brite would work on plastic bubbles. It's for ABS plastic so maybe not.

The only thing I know would work is using a peroxide paste and then letting it sit in the sun, but that would harm the pony inside and the card.

Thank you! Yes, that is what I thought, too. Everything would harm the pony inside the bubble aswell