If we're talking about grease stains on clothing, do *not* put them in the dryer. Period. That will make them three times harder to clean.
My go-to remover is Dawn dishwashing soap -- the original blue kind. It just works. I spilled a red, oily fruit salad dressing on cream colored material and I thought it was surely ruined. I saturated it with Dawn soap and then sprayed it with stain remover and washed it, then hung it up to dry. No more stain. It was completely gone. I turned and turned that material over and over, but I couldn't find a trace of a stain on it. I've since removed other greasy stains, especially cooking stains from clothing with it and it works like a charm.