Paul wrote:

If you were working with a patient with drug-resistant TB,
C.Difficile, and COVID-19, the cleaning procedure would
have to cover those too. Whereas a home user, you would
hope that drug-resistant TB isn't present. The TB thing
is one thing I feared at our local hospital. And they bring
people from remote areas, hundreds of miles to my hospital,
so they can cough on us :-) Well, they gotta go somewhere...
My hospital is pretty good about putting masks on people,
where their range of conditions include the possibility of
tuberculosis. The more trips I make to the hospital, the
more I learn about weaknesses in the system.

That's another reason for the gamma ray thing. An attempt
at total coverage.

It would be better to be making masks out of something "more permanent"
that can take a healthy dose of gamma. That would be a kind of
"end-to-end" design, rather than trying to retrofit a process
to something intended to be disposable.

Yes, definitely, if working or coming into contact with contagious
hospital patients I would want the best PPE possible, the full kit. I
am only messing about trying to re-use disposable masks to go
shopping, down the supermarket, say. And we are not suppose to deprive
our NHS front line workers of their stuff by buying up all the best
face masks, even if we could get hold of them, not to mention afford
them, that is.

I think I'm edging towards the compromise (until I get more supplies -
as needed) of maybe re-using disposable face masks, say 2 or 3 times,
by sterilising them in a pressure cooker. I'll review things as they
go along, and hope to keep healthy all the while.