I was in the waiting room at my doctor’s office when I struck up a conversation with two Hasidic women. They were only in their thirties, but between the two of them, they had 17 children. They braced themselves when I said I needed to pick their brains on something.
“How do I get those stubborn yellow stains out from the armpits of my kids white shirts?”
They had an answer: Spray the blue Easy-Off oven cleaner on the inside of the shirt where the stain is, and on the outside as well. Let it sit for an hour, then wash as usual. I tried it today, and the shirts are lily white. Baruch Hashem!