All he had to do was say "Instead of buying, we recommend making a cloth mask". The data in contemporary studies was limited at the time, but we had the historical experience of the 1918 flu suggesting that the simple masks used then were effective, and you get a win either way: cloth doesn't work, you still buy time and the population is predisposed to wear masks of any sort, even if they lose some trust in being given inaccurate reccomendations. Cloth does work, and it's even better.

As well, the aspect of HCW shortages, while real, inverts the "front line" of the pandemic to be in the clinics and ICUs and not ordinary gatherings. Prevent spread in the latter and you won't need so much of the former.

Fauci also made a mess of AIDS too, so his track record with public health is...questionable.