If it is dry, soak it in cold water for a few minutes to moisten the shirt. Remove the shirt from the water and pretreat with some laundry soap, a pretreating product such as ERA, Simple Green, or Totally Toddler Nursery Stain Remover. If using a powder laundry soap, mix it with some water to create a paste and rub the paste into the stain and let it set for ten to fifteen minutes. If you use any of the other products, just spray stained area until saturated with the product and let isn't set for ten to fifteen minutes. When washing use your regular laundry soap and some regular or color safe bleach in cold water, leave the lid open so when the first agitation cycle ends the washer will not go to the next spin cycle until the lid is closed, this allows the shirt to soak until the lid is closed and the next cycle can begin. I would let it soak in the washer for at least ten minutes before closing the lid. This may not be possible to do in a laundromat. Once the machine is done washing the shirt, check it to make sure the stain is gone, do not dry it if there is still a stain, it will set the stain into the shirt permanently. If it is still stained, put it back into the washer and wash again with detergent and bleach. Do not use hot water or dry the shirt if it still has a stain, the longer you let it soak, the better chance you have of removing the stain.
What I used if the stain wasn't already set was peroxide...blood stains on clothing rugs etc...it works well on fresh stains primarily- the suggestion above sounds good and if it doesn't work try the peroxide what do you have to lose..
You also try white vinegar on the stain mixed with a small amount of baking soda. Always soak and do not rub the fabric. As other writers have said do not dry until the stain is gone after soaking and washing. Good luck.
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