Can anyone tell me how to remore old black pet stains and the odors that want to linger? We just pulled up thirty year old carpeting and low and behold, lots of stains. So far we have tried a bleach and oxy-clean mixture. The smell has dwindled, but... and the stains have lightend some. Any other solutions? I will leave the floors bear if possible, but right now it looks like carpet will be replaced. Thanks