Hi. I have some experience with whitening thrift store finds, and here are my suggestions. One, if bleach did not take it out, then it is not an organic stain. Bleach is about the harshest treatment you can give to any fabric. The other pre- soaks probably helped, but you can let nature take care of it for you. If you are able, get the blanket completely wet, like dripping. Lay it out in the grass, in full sunshine. You will not believe how well the sun bleaches. To have full effect, you need to keep it as wet as possible, and should be in green grass. Flip it over, if necessary, and repeat. It could possibly take days to completely remove it. Cotton bleaches in the sun very well. The sun and green grass combination should also neutralize the bleach smell. If you can smell bleach in fabric, then it is not rinsed completely away. Un-rinsed bleach will continue to eat away at fabric, even after it is dry. Tumble drying stained fabric is the best way to set a stain permanently, for future reference. Based on everything you have put it through, if the sun cannot remove the yellowing, then I think it is probably a permanent stain. Hope this helps!

The vinegar should rid the blanket of the smell. LCB is alkaline, while vinegar is a mild acid and therefore neutralises the bleach. While I seldom use LCB anymore, when I do I always put a dose of vinegar in my softener dispenser.