Hand in Mouth

H is 6 1/2. She still puts things in her mouth constantly. Small plastic toys, nasty rubber bands, food that has been there for days, her fingers, her clothing and she would eat her hair if it was long enough. She picks her nose. She digs in her ear and today she confirmed my suspicion that she has been biting her fingernails. Way too many bad habits. I've explained the hygiene aspect of it. But she doesn't really care. I could punish the behavior which might get her so she only does it in private. But I don't love that idea. These habits are so gross and the longer they are done the harder they are to stop. Can I help her now? How do we stop these awful habits? Or do I have to wait until she wants to stop them? Any suggestions?