White sweater wear a long time easy to black how to do?

In the basin access to some cool water, not too much, as long as you can soak the clothes as much as possible, and then, the basin poured some hydrogen peroxide, that is, hydrogen peroxide, this bottle of hydrogen peroxide points are sold. Hydrogen peroxide and water ratio is 1:10, stir evenly, put the clothes inside the soak, about 5 minutes or so. Of course, you can also bleach them with 84 or bleach. When the time is up, just wash the clothes. There is another way, after soaking the clothes, use the soap to beat once, scrub a little, and then, then wash clean, next, beat the soap again, rub a few times, so that the clothes are evenly adhered to the suds. Then, take a transparent plastic bag, put the clothes with suds into the plastic bag. Put it in a sunny place, sunshine for an hour, halfway turn over a bottom, so that the clothes in the plastic bag fully sunshine. When the time is up, put it in a basin, clean it, and then, dry it up.