“We’ve found a homeopath! May we burn him?”
So there’s this homeopathic remedy called tuberculinum. Like the name suggests, it’s a derivative from tuburculosis pus.
Now, without this turning into a pile-on against homeopathy, I’m just curious what the process would be wherein a substance is transformed from pus to non-pathogenic substance.
IIRC, the whole idea behind homeopathy is that you do some sort of mega-dilution where the final solution contains basically nothing of the original substance. Which is disappointing for alleged remedies, but kinda fortunate for toxins.
Well, for starters, homeopathy means that they dilute the stuff so much that there’s actually barely a molecule left of the initial substance when they’re done preparing it. So there’s your answer for why this partucular product probably isn’t dangerous.
Lots of vaccines are made by killing viruses or bacteria so that they can’t actually infect the patient. They’re treated with solvents or heat until they’re just useless shells of their former selves, and the body produces an immune response aganst them without having them fight back at all.
Some use actual live organisms which have been carefully cultured to make them lose their dangerous (virulent) properties. Strains related to the disease-causing organism, but with little or no virulence themselves, can also be used.
When an organism’s toxic effects are from a toxin it produces, vaccines can be made by modifying the toxin slightly to make a toxoid, which looks enough like the real thing to cause a good immune response, but won’t do any damage.
So, in a sense, you can start with pus, or sputum, or any other pleasant infected bodily excretion you can get a swab into, plate it on the right media, treat it with the right chemicals, and get a working vaccine. Not quite as simple as mixing some pus into a solution and drinking it down, though. 
I just want to emphasize that the process of vaccine production is not in any way comparable to the homeopathic process. They’re wildly different processes. I understand what you’re saying - I just don’t want anyone to be confused. As for the OP, yeah, I’d guess it’s the massive dilution process that’s keeping the creators safe from litigation.
Safe from the litigation caused by killing someone, yes. Safe from the litigation caused by selling a ‘cure-all’ that cures nothing, not so much.
We’ll see how long the practitioners of this crap last before the authorities crack down.