I found however that it does not work very well for old bloodstains unless you do the following found this tutorial idea.
Removing blood stains from carpet with hydrogen peroxide.
If you don t notice any color changes dip a cotton swab in hydrogen peroxide and apply it.
Last but not least use a mixture of hydrogen peroxide to remove the bloodstain on your carpet.
Removing heavy duty blood stains.
If a stain remains after trying to remove it using one of these other methods try saturating the stain with full strength hydrogen peroxide.
It is fairly inexpensive which makes it a cheap stain fighter to keep on hand for household use.
For this method you need a bit of hydrogen peroxide.
Repeat if you see it can use.
Hydrogen peroxide is generally really great for removing blood stains on fabrics and doesn t usually bleach the material either though it might so test a small area first if you are worried.
Hydrogen peroxide is safe for fabric.
You can also try cleaning the stains with shampoo and ammonia.
If needed you can repeat the procedure.
To remove blood stains from carpet apply hydrogen peroxide to the stains and let it dry completely which will lighten the carpet fibers and hide the stains.
In the case of old or stubborn stains reapply as needed.
First mix shampoo and water and apply the mixture to the stains.
Just apply a small amount of hydrogen peroxide directly to the stain and watch as the red blood stain disappears.
After the time is up blot the area with a clean cloth.
How to use hydrogen peroxide on carpet stains.
How to remove blood stains with hydrogen peroxide and hot iron.
It is important to note that hydrogen peroxide can bleach items and damage colored surfaces or fabrics.
This works with wet and dry blood depending on the fabric.
Try hydrogen peroxide next.
And leave it squeaky clean.
Test the hydrogen peroxide in a hidden spot first to make sure it doesn t change the color of the carpet.
Before deciding to use hydrogen peroxide note that it may bleach or weaken certain fabrics and can cause stains itself.
Hydrogen peroxide often is used as an antiseptic and a disinfectant but it also is useful for removing stains.
Buy a bottle of 3 hydrogen peroxide from the drug store old solutions do lose potency pre test the on an inconspicuous are of your carpet.
Moisten the stain with this mixture and let it sit for approximately one hour.