Hot water Tide w/ Bleach.
As I understand it that its just oxygen bleach. But Tide takes out stains that are hard to get out.
I do an over night soak for my whites in oxygen bleach, Calgon, and Tide w/Bleach. It will takes out every stain we get, even ones that have been supposedly set in the dryer. We are very hard on our clothes so thats why I go through the above routine to get them clean.
My sheets are washed in hot and Tide, no soaking. My dh has a very oily head so his pillowcases are pretty nasty. They wash out each and every time.
Calgon holds the dirt in suspension in the water and strips the fabric.