How can i remove dried blood from a mattress? The stain has been there for over four years. I tried to remove blood stains from my mattress wtih vinegar and baking soda, its worked for me!. You may apply this method on urine and blood stains also.1  Howto & Style. tried to remove blood stains from my mattress wtih vinegar and baking soda, its worked for me!. You may apply this method on urine and blood stains also.