Hi C., I cannot state positively that Nature Bright will take out set-in oil stains; however, it has eliminated many other set-in stains that have been washed and dried several times. Nature Bright, in combination with Shaklee's detergent, is an extremely powerful stain remover. It is a laundry booster, and we use it instead of toxic bleach. In fact, all of Shaklee's home cleaning products are non-toxic. Yes, I am a Shaklee distributor, and I am responding to your question about getting the set-in oil stains out of your clothes. I am in Georgetown; where are you? If you are close by, I am more than willing to give you a sample of both to try. If it works and you would like to order some, you can do that right at my website www.emilytaft.com What I would suggest on these stains would be to dissolve a scoop of Shaklee's Nature Bright in warm water along with a teeny,tiny squirt of Shaklee's detergent (you can do this in sink or a bucket). After all is dissolved, rub a tad of detergent directly on the oil stains & put the clothes into the sink. It's a good idea to weight them down with something heavy to keep them under water. Just leave them for several hours or even a day. Then, rinse gently, wring them out and throw them into the wash. Again, I would add one scoop of Nature Bright (dissolved in warm water)right on top of the Shaklee detergent in the proper receptor on your washing machine - then start the wash. That's it. Please contact me with any questions or for us to connect so I can give you a sample of each to try. Call me at ###-###-#### or e-mail me at ____@____.com - hope this helps. E. Taft