This isn't really going to help since it's after the fact, but for future reference, protein stains like chocolate, kool-aid, juice, blood, feces, etc -- you should soak the garment in cold water with no soap, detergent, or anything. Most times it will come out on it's own simply from soaking.
NEVER use hot water on protein stains. Heat opens up the fibers of the garment and allows the stain to set, plus it kind of "cooks" the protein making the stain worse. Cold water tightens the fibers, making it easier for the stain to "release".
I have yet to find a stain remover that actually works. I've tried oxy-clean, spray and wash, shout, etc. A while back "orange clean" was the thing, and that never worked for me either.
I have had a few stains that I've missed and didn't soak set in, and I've used dawn dish detergent to scrub them out, and that seems to work most of the time - but that's about it.
But cold water soaks almost always work for us :) And we sure do have stains (I've got 3 boys, lol, and one not-so-messy girl).
Good luck getting the stain out! I hope you find something that works!