breastmilk up the nose! No! Really! Ive done this with all my babies, especially when they are nursing and cant breath through their nose. I just squirt a little breastmilk in their nose, clears them right up!
I'm guessing you're asking about best way to nurse the baby when her nose is all stuffed up. I would use a nasal syringe and try to clear things out as best you can before nursing, and then use the football hold, which keeps the baby's head somewhat upright.