How do I clean oily dirty carpet stains?

Your best bet is to try the commercial Bissell carpet cleaner. It works well for most stains. You will have to use a pre spot treatment before using the actual cleaner. Good Luck!

If you have ever heard of something called traffic film remover it is used for washing cars. You can buy from any good motor shop it's a heavy duty degreaser and will lift any stain. Use this as a pre spray than suck it up with something like a rug doctor.

Your carpet probably is a synthetic which is an oil based product, oil based stains become a part of it and basically get set into it. You'll never get it out completely. The best you can do at this point is call in a pro carpet cleaning co.

Dawn Ultra on spots rub in gently with fingers let sit to break up grease then using hot wet washcloth surface scrub very gently, blot with dry towel to soak up excess then rinse repeatedly with wet wash cloth blotting with washcloth repeat until all residue is out of carpet then blot with clean dry towels. don't hard scrub spots you will push the oils down into carpet,into any carpet pad. if you need to stand on towels to get excess moisture out it's easier.get all soap out of carpet or it will make additional dirt stick onto carpets fibers. if you have shop vac use it to pull out excess moisture.

I’ve always been a fan of Spot Shot. The stain one in a can not their regular carpet cleaner. Not sure about oil.

Use 1/4 cup of white vinegar, 1 tbsp. of Dawn dish soap, and fill with water. Spray area liberally and let soak for 5-10 minutes and then proceed with blotting with a clean, dry towel until stain is removed. Some carpet stain removal products can be of great benefit for combating many types of carpet stains.