I’ve wondered the same about colloidal silver. If I’ve been in contact with a person who’s got a cold, I gargle with it, and also have some in a spray bottle which I’ll occasionally “snort” some of. (I haven’t gotten sick in a good long time - decades, with the exception of a cold that lasted about 12-16 hours.)
I had not thought about it till now. My hubby had a terribly bad respiratory infection for 6-8 weeks last fall. He refused to go to the doc or be tested. I also had what I thought to be a cold the first day he was sick. My one day to his 6-8 weeks. But I rinse my mouth with peroxide and on other days spray mouth with colloidal silver. Perhaps that was our difference.
You’ve reminded me of when I had strep throat, never had it as a kid, then after a long duration with it, my mother told me
to go see a doctor, well even without the lab result the doctor prescribed amoxicillin and sent me on my way. Something else,
garlic has a similar substance, so I take 3 garlic gel-caps 3 to 5 times a day until the bottle is gone, if I start to feel a
sore throat thinking it possible to avoid another doctor visit. I think bulb of the garlic is the part that is most potent.