I have a 4 yr. Old haflinger mare with a long, thick tail that is orange at the bottom from urinating on it for the past 4 yrs. I got her last July and have tried washing the heck out of it to no avail. Used the whitening shampoo, bleach (which I don't like but tried anyway) blueing and repeated washings. Any body know how to get this stain out? I intend to bag it if I can ever get it clean.