Shout Laundry Stain Remover is sold in convenient bottles, somewhat like dishwasher soup bottles, that you can open and close without actually taking off the cap. Larger jar are also available, allowing you to refill the small bottle. The application of this stain remover is very simple: you put some on the stain before washing the clothes, rub it in (I usually do that with the tip of the bottle, after closing it), then load the clothes in the washing machine & wash.
I have had mixed results with this product. Some stains come off, others only fade, and some stay unaffected. I have noticed that Shout works best on fresh stains; it had successfully removed some nasty fruit and vegetable juice stains for me when I had used it right after spillage. Also, after several cases of discoloring, I have stopped using it on colored items. So I guess my recommendation would be this: Use with caution and only on fresh stains.