For tough carpet stains try mixing 1/2 cup salt, 1/2 cup baking soda, 8 drops of white vinegar, and a small amount of water to make a paste. Spread the paste onto the stain. You can just let it dry or you can work it into the carpet for really tough stains. After the paste has dried, brush with a stiff brush and vacuum. Don't brush too hard as not to damage the carpet. This is a very powerful carpet cleaner so be sure to test your carpet for color fastness.
This worked great for me when we
rearranged our bedroom furniture. Years ago I spilled a pop on my night stand. I quickly cleaned the spill then; however, when we
rearranged the bedroom, I found that some of it had gotten under the night stand. I tried several
commercial cleaners and this paste was the only one that worked.
Let me know how it works on your stains. I think it is the best homemade carpet stain remover.