Carpet Stain removal remedy you can manufacturer yourself.

General tips on stain removal: Clean up spills as fast as you can. Blot or scrape up as much of the spill as possible, blotting from the outside toward the center. Test the stain remover on an area under the sofa and wait 15 minutes to see if it damages the carpet color. After you clean the carpet, blot it dry and weigh down a small cushion of paper towels with a heavy object to soak up all the moisture. Don't panic!

General stains:
Borax*. Use according to label directions. Borax can be toxic if ingested.
Blood stains:
Cold water or Club Soda. Sponge stains immediately with cold water or club soda and dry with a towel. Repeat as necessary.
Ink stains:
Cream of Tartar and Lemon Juice. Place cream of tartar on the ink stain and squeeze a few drops of ice on top. Rub into the stain for a minute, brush off the powder with a clean brush and sponge immediately with warm water, being careful not to saturate the carpet backing. Repeat if necessary.
Isopropyl Alcohol* Be sure to wear gloves and work in a well-ventilated area. Blot rubbing alcohol onto stain.
Non-oily stains:
Vinegar and Liquid Soap. Mix together 1 teaspoon of white vinegar, 1 teaspoon liquid detergent, and 1 pint lukewarm water. Apply this mixture to the non-oily stain with a soft brush or towel. Rub gently. Rinse with a towel dampened in clean water. Blot dry. Repeat this process until the stain is removed. Dry the carpet quickly using a fan or blow dryer. There is a chance that vinegar may bleach some dark, sensitive colors, so try it on an inconspicuous area first.
Soot stains:
Salt. Sprinkle the area generously with salt. Allow the salt to settle for at least 15 minutes before vacuuming.
Stains and odors:
Vinegar and Liquid Soap. Vinegar will kill the odor of urine and prevent staining if you can get to the spot right away. First absorb as much moisture as you can with dry paper towels. Next rinse the area with warm water and apply vinegar and soap solution into the stain using a clean cloth or paper towel and leave on for 15 minutes. Rinse with a towel dampened in clean water and blot dry. There is a chance that vinegar may bleach some dark, sensitive colors, so try it on an inconspicuous area first.

Or you can buy a complete spotter kit for any type of spot removal

Buy the Complete Spotter Kit