Hydrogen peroxide. A 3% hydrogen peroxide solution, which is the strength it is typically sold at, can be poured directly onto the stain or applied with a cotton ball.
Be aware that it will likely bleach colored fabric.
Keep the fabric in a dark place for 5-10 minutes, since light breaks down hydrogen peroxide, then blot with a sponge or cloth.
1. Turn the fabric so the stain is face-down.
2. Flush the stain with cold water.
3. Rub soap into the stain.
4. Rub the stain against itself.
5. Rinse and repeat, if necessary.
Check out more of our Tips And Tricks