Wanted : washing tips!

Not sure if this is in the right section, but here goes.  I have two MAM astronauts, but one of the space suits has gone a bit creamy yellow.  I've tried washing it a few times with different things (like Vanish).  I did think about bleaching it but I'm not sure if that would affect the coloured bands around it.
Does anyone have any tips on getting whites back to bright white?

Hi Pete, get some Sterident tablets (for cleaning false teeth) put two tablets in a sealable tub with hot water, drop in astro suit and seal for a few days. It will be really clean when tey come out. For more stubborn stains, add more tabs and leave for longer. Hope it helps mate.