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/
Hmm I have used either that stuff or petroleum jelly in my nose in the winter at peak flu times because the cold winter air gives me nosebleeds and it's a good remedy for a dry sinus. Perhaps I reaped another benefit without knowing.