well I have bleached 2 yellowed keys...and it works !!! I guarantee
the process took aprox 72hs ...but I think more yellowed=more time
after long time we find a real solution for this !!!! yes !!!!!
thanks Kristian95 for bring the info here to EAB!!!
I haven't used light or heat as acceleration of the process....it doesn't need it...only a small flask inside my house away from light or heat........tomorrow I will post some pics