Stubborn sweat stains — those gross, yellowish patches that can develop around under-arm seams — can ruin otherwise perfect white T-shirts. Luckily, a popular lifestyle blogger has revealed her surprisingly easy trick for getting them out — and it only requires four things. Utah-based author, blogger and mother-of-four Jill Nystul shared the simple and effective how-to on her blog, One Good Thing, breaking down how Dawn dish soap, hydrogen peroxide, baking soda, and a scrub brush or toothbrush are all you need to make your white tees as good as new. Before and after: Utah-based author and blogger Jill Nystul shared the simple and effective trick for removing sweat stains Jill came up with the trick not long after her two sons joined a church basketball league and started tossing much dirtier shirts in the hamper. ‘Their white undershirts took on yellow sweat stains at the armpits that just wouldn’t budge, no matter what I tried!’ she said. ‘I even tried pouring straight bleach on the stains at one point, and still, those stains stayed put. But I was determined to find a solution to those stubborn stains!’ First, stir one part Dawn dish soap with two parts...