What material? Tried the typical oxiclean?
First spray with Shout or the like. Cover with Oxi. And let soak in machine over night. Almost always gets stains out.
Will that work even on a old stain? It's been washed many times already...
Sometimes have good luck on old stains with Amodex
+1 but I wouldn't recommend the brush they sell to use with it, it's pretty rough and could ruin fabric if you're not careful. (Test in a hidden area, or just rub it with your fingernail or something less abrasive)