ok, went and looked up white brite, it is a sulfite meant to take out mineral or rust type stains. look for either enzyme stain remover (gets meat, urine, coffee, etc) or oxy based products (removes soap stains, makeup or dye type stains,
yellow from chemicals such as deodorant and perfumes)
Use separately. rinse the blanket and dry completely before commencing each treatment. If one doesn't take the stain out, the other might. best wishes

Try Oxyclean. My cousin collects antique linens and swears by the stuff. She soaked some yellowed lace curtains in Oxy and they came out snow white. You might also try asking your local Dry Cleaner. They have cleaning methods, solvents and chemicals available that most people cannot buy.

This post was edited by jannie on Mon, Jul 8, 13 at 9:30

If there is a clear line of demarcation on the blanket, the yellow may have come from folding the blanket and storing it with one side touching a wooden shelf or cabinet. Luckily, most yellow stains come out as long as you haven't put the item in a hot dryer and set the stain. I have used Mama's Miracle Linen Soak on sheets, pillowcases, old lace doilies, and vintage baby clothes—some with terrible stains— and I don't see why it wouldn't work just as well on a cotton blanket.

Miracle Magnolia could you please share the ingredients in the Mama's Miracle Linen Soak that you've recommended?

Yes, I'm looking at the label and it says sodium perborate, sodium carbonate, sodium chloride, and biodegradable surfactant.

Thank you