A.T.
For really stubborn stains I've soaked things overnight in a combination of very hot water, 2 parts chlorox color-safe bleach POWDER and 1 part Cascade (in the green box) powder. Sometimes I have to do this for several nights. Then rinse really well. Most should come out. If the stain is still stubbornly in the dress, I then put the color-safe liquid bleach on the stain and let the garment dry completely. BUT DON'T PUT IT IN THE DRYER. If you've put the garment through the dryer, you may have "set" the stain.
Good luck!