Pods! They're from Tide! And they're free! Apparently it's a detergent/stain remover/clothes brightener all in one handy little... pod, if you will. Fill out the form on Facebook and get your free sample.
The page was running a bit slow earlier, but it seems to be OK now and they have tons and tons of freebies to give away, so don't panic about that stubborn stain just yet.