Now would be a good time to try my borax theory, which, if nothing else, might remove any yellowness *induced* by the bleach.
Borax theory, normal version: Take about two tablespoons of borax and a sponge soaked in warm water; scrub.
Borax theory, soaking version: Heck if I know; mix up a good amount in hot water, and soak the plastic in it. If nothing else, it might oxidize any 'bleach yellow' (as you can sometimes notice on your socks) to a 'pure white' tone.
Of course, others have said borax scrubs alone don't seem to counter the Amiga yellowing, because it was a defect *in* the plastic, instead of just the usual mix of atmospheric tars and oxidation on the surface.