In a nutshell, we showed that over-the-counter cheap generic antibiotic neomycin can be repurposed in nasal formulation to prevent & treat infection, block transmission, and reduce disease burden against a wide array of viruses. Since this is a host-directed strategy and virus-agnostic, it holds promise as a prophylactic strategy against any viral threat.
The advice in the screencapped thread was to apply a little with a q-tip to the inside of the nostrils.
There is no info on any dangers of doing this very often, but if you can't avoid a high-risk environment it's worth trying.
Here's a thread about the study. https://threadreaderapp.com/thread/1782535781338222960.html
here's the study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5918160/
There's an old folk remedy that putting petroleum jelly around your nostrils helps hayfever, by absorbing pollen, I imagine that could be what's happening here.
you have nothing to lose but your grains