i use asda's own brand liquid machine wash but when i do a whites wash i add a scoop of the stuff you're talking about, and i have to say it really does work. i believe it contains 'brighteners' which make your whites look really, really white. i don't use it as a stain remover, just to keep whites (towels, sheets, t-shirts, undies) really white. as to whether or not it's worth the money, only you can decide that if you try it. i'd give it a go and see what you think.