Nylon fabric is like an oil magnet, so if you get oil on a pair of nylon athletic shorts, try to take care of the stain quickly. Also, make sure the stain is gone before the shorts go in the dryer. The dryer's heat can make oil stains permanent. You have options for oil stain removal when it comes to nylon shorts, depending on how much effort you want to put into it and how much you want to spend.
Really, there are no big shocks coming for those of you experienced in fabric care, this is all pretty much common sense and for that matter, it applies to most fabric types.
Take it to the Pros
The easiest way to get rid of an oil stain on a nylon garment is also the most costly. Take the shorts to the cleaners and let a professional take care of it. If you do this, make sure to point out the stain and mention that it is oil. Examples of oil stains include cooking oil, motor oil, and oil-based cosmetics. Knowing the stain's source increases the likelihood the dry cleaner will be able to get rid of it.
Stain Remover Sticks and Spray
Purchased stain remover sticks and sprays provide a slightly cheaper alternative to visiting the dry cleaner. Check the directions on the container before you start, but most brands offer similar directions. Coat the stain with a thick layer of stain remover. Fold up a paper towel and place it firmly on the wrong side of the fabric. Then fold a second paper towel and dab inward from the stain's outer edge. Repeat as needed until the stain disappears, then launder the shorts according to care tag directions.
The least costly but most labor intensive oil stain removal method is to use laundry detergent. If you're using powder, mix it with water to make a thin paste. Saturate the stain with detergent and let it soak in thoroughly. Then, fold two paper towels. Don't scrub from side to side no matter how tempting it is. Place one paper towel under the fabric and use the second one to gently wipe inward on the stain. Repeat three or four times until the stain is gone.
Set-In Oil Stains
While it is possible the stain will be permanent if oil-stained shorts make it through the dryer, it's still a good idea to attempt stain removal on the slim chance of saving your garment. Soak the stain in stain remover spray or a water-diluted detergent solution for at least half an hour, then use the two paper towel method and dab inward on the stain. Soak the stain again if it does not come out in the first try. The extra soaking time increases the chance you will ditch the stain.