How do I clear up a dog's sinuses?

My austrailian cattle dog is sick. I have already taken to to the vet and the medicine plus the injections are not helping. I have wiped her nose with warm washrags and even tweezed out the boogers....is there a way to get the rest of the "stuff" flowing out? I don't want to be digging in her nose and hurting her but I want her o be able to breathe more clearly.I know for people it helps to be in a steamy room, like a bathroom during a hot shower...does this help for dogs too?Thanks in advanced.She is a 2 year old Aust. Cattle dog. She lives indoors. We found her as a stray a few weeks ago and she was not having these problems then....she also won't eat and has been throwing up yellow stuff.

some more info would be helpful: age, sex, living environmentwhat medication has she gotten....specifically?reasons for nasal discharge in dogs: allergic rhinitis, dry environment, foreign body, tumor, fungal infection, distemperdon't tweeze the stuff out...a warm, wet washcloth to loosen the debris is fine-Dr. Kate