Really? That would be awesome. Except...where can I get huge quantities, because my garden is going to be quite large. At ~$3 a gallon, that would be a pretty pricey endeavor if I have to buy it at the grocery store!
If you've got a large area that's just made up of grass that you want to kill, you can put down several layers of newspaper over it, then mulch over top. That'll smother the grass, and when you get ready to plant you can just dig holes right through the newspaper. Or rent a sod cutter and remove it that way. Of course if the grass is intermingled with things you want to keep then neither of those approaches will work.
No, it's just a hay field we want to convert. But we need to plant soon, so I don't think there'd be time for the newspaper to do it's work. We may just have to till and then put down the landscape fabric we bought and hope for the best. We'll need to put lime down too - is that okay for organic?
Lime is OK, organic, but be sure your soil is really acid before you use lime. Many people think they need to when they don't. I'm not familiar with OK soils, but here in the Midwest our soil is already alkaline for the most part. You can get inexpensive pH soil testing kits at any garden center or big box store.
I'd go ahead and till your area to get rid of the grass. If you can rough till it, then let it dry out in the sun for a week, then till it again, you should kill most of the grasses. Plan to mulch, either with fabric or newspapers and leaves, etc. and you should have little problem.