I commented on your link, the contents of which are replicated above, so all I can say is see my above response.

Which is, to recap, I don’t know of any public announcement calling for people who aren’t sick to wear a mask.

And there are no studies showing the efficacy of zinc in a real world setting. Of course I could be wrong. And the rest of the advice seems spot on.

I’ve been wrong before! 😉 I could be again.

I can’t find much about the “expert” online. I haven’t found where his advice was first posted. I’ve read plenty of comments from experts, though, who say buying face masks is a bad idea for anyone not infected with the coronavirus.

And I have found nothing on the web about zinc having more than a slight effect on anything other than the common cold.

So until I see evidence that Robb is for real and I see evidence supporting his contrarian claims about zinc and face masks, I’ll be be skeptical about his advice.

The misinformation attributed to Robb seems,
to me, to be designed to help drive up the sales - and price - of face masks and zinc. Or it might be a way to stir up confusion and apprehension among the public.

From the paper:

“Details on the effect of zinc ions are currently largely unknown for nidoviruses. This large group of positive-strand RNA (+RNA) viruses includes major pathogens of humans and livestock, such as severe acute respiratory syndrome coronavirus (SARS-CoV), other human coronaviruses..... (PRRSV) [17], [18].

And details, 10 years after the publication of this study the effects of zinc ions, are still unknown.