How can i remove really grubby stains from a pink wool jumper?

I have a pink wool jumper and it has some really dark grubby stains on, i was wondering if there was anyway i could get these stains out? otherwise the jumper is ruined

How can i remove really grubby stains from a pink wool jumper?
I have found for removing a fat or oil stain -- or the oily component of a more complex stain such as salad dressing or gravy (once it's dry) -- is to rub cornstarch (or cornstarch powder, or even talcum powder) into the stain , let it sit for at least 20 minutes, and then brush it off with a dry washcloth or soft dry brush. You may need to repeat the treatment several times to fully remove the fat. It works especially well on silk and wool