All of them are supposed to be applied directly to the stain and left for several minutes before washing. Testers took swatches of fabric soaked with tough-to-remove stains such as coffee, blood, wine, motor oil, and cocoa. They applied the same amount of each cleaner to the stain, let it sit for 5 minutes, then washed the swatches with detergent and a full load of towels.
Testers also washed the stained fabric with detergent but without pretreating the stains, to see whether the products really made a difference. Testers analyzed the swatches with a colorimeter to determine how much of the stain was removed.
While Resolve Foaming Aerosol says it's "amazing," it wasn't. Actually, it didn't do a great job on most of the stains. And Shout Advanced Stain Lifting Aerosol didn't do much better. In fact, none of the stain treatments did a great job at removing cocoa. Still, most of the stain treatments did do better than just using detergent alone.
In the end, it was Resolve Spray and Wash that removed the most stains. And at 10 cents an ounce, it's the cheapest product tested.
Another second stain remover did almost as well in Consumer Reports' tests. It's Shout Advanced Action. Unlike Resolve, it can be applied up to a week before you do your laundry.