1/ NIH published study: N95 masks don't stop all 80nm or smaller virus, surgical masks much worse. (no scarves listed, my guess far worse)
NIH published Electron microscopy studies of the coronavirus show size ~80nm with some misshaped & smaller.
https://www.ncbi.nlm.nih.gov/pubmed/16490606 

Electron microscopy studies of the coronavirus: 2017

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5326623/

AntiViral mask "BioMask" by Curad invented 2012 is coated with citric acid, copper, & zinc..slays coronavirus within 1 minute.
Made in China.
Was already out of stock Jan. 30th 2020.

We are sending our healthcare workers and first responders into battle wearing N95 masks that the NIH knew years ago were not effective. The people who created pandemic plans never bothered to recommend that the public have access to inexpensive (50 cent apiece) anti-viral masks.

I'm just appalled at how COMPLETELY defenseless and unprepared our country is to stop this coronavirus, when it's apparent that had we invested a few pennies per citizen in anti-viral masks a decade ago, this pandemic would have ended quickly.
2010: https://www.researchgate.net/publication/44889521_A_Novel_Anti-Influenza_Copper_Oxide_Containing_Respiratory_Face_Mask

It's ridiculously easy to produce anti-viral masks with copper, but as the man in the video says...I am NOT saying this process would work against coronavirus, but I agree with video guy, it's worth a try, given how useless @CDCgov has been in this area.

I am not a pandemic expert like Fauci or Birx, but it occurs to me that had the USA invested a billion bucks in antiviral masks, every citizen would have a package of them, and when the outbreak hit our shores, CDC could have said "put on the mask", and 2 weeks later it's over.

Why is it that the experts advising @realDonaldTrump aren't demanding he use the Defense Production Act to IMMEDIATELY start making & distributing these masks to every person in the country?

The health experts seem most interested in protecting members of their own profession.