Sorry to say that as much as I think that natural/homeopathic remedies are quite useful for many things, Parvo is not going to be one of them. I have seen a few dogs and puppies die from parvo and it is not pretty. It doesn't happen very often where I live because there are many low cost/free vaccine clinics in the area, but every so often a dog/puppy(s) will come into a shelter with it.
Sounds like you are doing everything you can. A/D canned food works very good for stuff like this, as gross as it is. My foster kitten I have now was in pretty bad shape when I got her and I just did SubQ fluids (lactated ringers), Nutrical, force fed A/D and baby food, Doxy, Clavamox and Cefa-Drops, Terramycin for her eyes and sores.. I've had her since the 5th and she is doing fine now.
Parvo is hard to beat.. I don't know of many pups that have survived it even with hospitalization. Good luck
My cat is smarter than your honor student.
Stop Dog Fighting ~ Neuter Mike Vick!
~ RIP Timmy ~ May 2009 - November 6th 2009