Has anyone ever heard of Parvo K?

I just started fostering on my own again (used to run a group but politics is not my strong suit). Well I got a puppy that was pulled from a GA high kill shelter and wouldn't you know he contracted Parvo during the transport with 40 other dogs/pups.

I have treated Parvo before, SubQ fluids, enemas, antibiotics for secondary infections. Anyway my vet back home suggested ordering this stuff. It worked with the second dose. No vomit or diarrhea in 12 hours and he just started symptoms yesterday. Has anyone else ever used this stuff? I am curious if this puppy just happened to have a really strong Constitution or if its actually this stuff.?