I'm finally getting around to organizing and storing clothes LO's outgrown ... and I'm finding yellow stains on almost every neckline, though they were definitely washed clean and line dried in the sun after last wearing a few months ago. Google tells me this happens from milk proteins in the fabric over time. Okay. So they looked clean, but weren't totally, apparently.

So my question is - would it do any good to do oxyclean etc and try and get the stains out now before I store them, or will they just reappear again by the time I hopefully pull the boxes out in a few years for #2? Anybody have experience with this? Secret method to be sure the stains are gone for good if I do wash again now?