I have some beautiful, high thread count white cotton sheets. Unfortunately, I had a nosebleed and have some bloodstains on the pillowcases. I've tried using the Clorox bleachstick, to no avail. Any suggestions as to how to remove these spots? They have been washed and dried numerous times, to make matters worse. I have not soaked the pillowcases in bleach since cold water washing is indicated on the label, and because the cotton is soft.