The following comes from The Tightwad Gazette and is the best stain formula I have ever tried. Just make sure you test your items for colorfastness prior to use.
2 cups color safe powder bleach
2 cups Cascade powder dish detergent
5 Gallons of super hot water
Mix it together letting everything dissolve before putting the clothing in. You will want to wear gloves. Add the clothing and let it soak overnight. If this does not get your stains out nothing will. I put mine in a cold water express cycle in the washer after to remove the soap. I have found it useful to keep my stain bin right next to my washer that way when something will not come out in the regular wash I simply add it to the bin. when the bin is full it's time for a stain wash. I use a 16 gallon plastic tote for my stain washes.