How do you remove old, dried on cooking oil stains from cotton fabrics?

The cooking oil stain has gone through the washer and dryer a couple of times and hadn't been noticed until recently. Is there any way to remove this old stain or are old oil stains pretty much set in?How do you remove old, dried on cooking oil stains from cotton fabrics?
Dawn dish detergent works wonders, even if it's been through the washer a few times. My boys constantly use their shirts for a napkin and most of the time I don't notice the oily stains until the shirts have been washed and dried and I'm about to hang them up. Dawn has worked every time I've had that problem.How do you remove old, dried on cooking oil stains from cotton fabrics?
It might be there for good. I would try spraying it with a spot laundry cleaner like Shout and letting it sit for a week then launder as usual.

Good luck.
well you can try with baking powder , add a tablespoon of baking powder to a small drop of water , lay over the stain %26amp; leave for 10 min麓s or more , not sure if it will lift out now as you say you have already washed it . wash in cold water
Try mechanics hand degreaser then machine wash as usual. Available in auto parts stores and Big Lots. Prices start at $1.00 for a canister.
I use Dawn dish Liquid. Apply water to the stain and then apply the dishliqid undilluted. Let it sit overnight and re-launder.