How do I remove an unknown stain from my carpet?
If your carpet is a light color then try white vinegar on it first. I use this for pet stains and its light years beyond any product specifically formulated for stains and 1/20th the cost. It kills germs/bacteria/mold. I pour the vinegar straight from the bottle onto the stain, thoroughly soaking the carpet. It will begin to react with the stain and start fizzing. Once the fizzing stops you can soak it up with a paper towel but its best if you use a steam cleaner with just water in the tank to remove as much of the vinegar and the residual odor as possible. It will have a strong odor that will completely dissipate after two days assuming you sucked enough of it up after application.