My best luck with stains or grease spots has been to take a bar of ordinary soap, wet the corner and rub the soap into the spot. Let sit, wash/rinse, (don't dry), repeat as necessary. It's ok if it sits and the soap dries in, just wash it and repeat as necessary. I've gotten ink out of a ball cap, grease out of work shirts, and multiple other things out. Exposing to sunlight may help, it works for mustard stains.