And... Done!
Last night I soaked the pillowcases in a concoction of a full scoop of OxiClean, a full OxiClean scoop each of Borax and Baking soda, about 1/2 cup of Awesome degreaser, and about a load worth of Tide. Also a squirt of Dawn for good measure. All mixed in a bucket of HOT water. The water started turning yellow almost immediately, I let them soak for a couple hours while we went out to dinner. Came back and rinsed them out thoroughly, then washed in HOT water with a Tide pod, a scoop each of Baking Soda and Borax, and about a cup of bleach. The results- Spotless. No yellow to be seen. Also did the same to the sheets (although in the washer) and a little lighter on the products. Soaked those overnight, washed this morning. All look like new. Sheets/pillowcases were 60% cotton, 40% polyester.