There's a new yellowing remover that's currently being tested at yojoe.com forums. More info at http://chemkitdepot.com/plasti-bright.aspx

Interesting. If it doesn't require soaking the parts in liquid I will definitely check it out.
I have a quite recent Bandai toy that turned out to be insanely prone to yellowing on certain parts and it's been bugging me for a while now. Thought about trying the hydrogen peroxide trick, but ultimately I didn't want to ruin the stickers as getting replacements wouldn't be possible.

Unfortunately, soaking is required, although the time should be considerably shorter and no UV is required.

Interesting! Have been trying Retr0bright a few times without decent success (could never find the proper mixing ratios anywhere!), so this definitely deserves a closer look.

Thanks for sharing!

EDIT: Hm, the first link is to a store with zero descriptions and YoJoe.com doesn't really show anything either… :-/ Anyone have any links to share on this?

There's some discussion about the stuff going on at Amibay. The site chemistry gurus seem to have come to a conclusion that the effective ingredient might be oxalic acid (as in rhubarb). They've acquired some and are going to run some tests of their own. I don't seem to be able to either view or register into the yojoe.com forums as my IP address has been banned by the administrator.

Amibay also has a great Retr0bright support thread.

Edit: Here's a direct link to the yojoe.com forums, where plasti-bright is being discussed. Not able to view it though due to reason mentioned above.

Rhubarb? Cool! I have loads of that in the back yard (once they've grown fully!)

I'll keep a watch on those threads (don't have time to read 18+ pages right now), 'cause my own tests with H2O2 were less than spectacular.