Parvo is a very easy virus to avoid if you just VACCINATE your pets. This means taking you puppy for regular visits to your veterinarian to be vaccinated properly. This does NOT mean purchasing vaccines at the local store and giving them yourself. Once a dog/puppy gets Parvo, there is only a 50/50 chance of survival NO MATTER WHAT YOU DO! The Parvo virus itself doesn't kill dogs, the effects of Parvo, such as dehydration, secondary infection, hypoglycemia DO kill dogs. Supportive care is important. IV fluids, antibiotics, anti vomiting medication, etc.
If you take in a stray puppy and your other pets are not vaccinated, you should keep that puppy separate from your other pets for 14 days. JUST VACCINATE!! Dogs that have survived with all of these "alternative" treatments were just on the lucky side of the 50/50 chances of survival.