Go to any carpet cleaning company see if they will sell you coffee kicker or vanish . then use half a cup of bleach WITH coffee kicker let is soak for a few hrs and I will come out bright but make sure you don't get any on your hands if you do wash with cold water . ps I work with these kinda stains all the time what has happen is the fibers have oxidized - off gas. you need to bring the ph chemicals down in the fibers .been dealing with these kinda problem with carpets for 20 plus years..ps if you can find picerton very hard to find that would work to ...yellowout works to, but it can damage fibers easy very hit or miss but it works well
We just tried the Dawn Liquid Dishwash Soap on a heavily yellowed ( from sunscreen) white Hell-raiser Tank top ,,, and it worked GREAT .
