Try using hair spray. Learned this trick when teaching and a kid marked someone's pants with a marker. The ink came right off. I used the cheapest one I could find...Aqua Net.
Another girl spilt a bottle of fruit drink in her new sweater. She said her mother was going to kill her! I gave the sweater to the school's secretary and she poured boiling water on it and the stain came right out. I sent the wet sweater in a plastic bag home with the student. I also gave her my home phone in case her mother didn't believe her or was wondering why the sweater was so wet. I do that with avocado stains too which my detergent could not get out.