With people boiling, soaking and baking their razors to sterilize them, there isn't much talk on what to to with vintage brushes. How do you clean them for use?
let that hairs soak in a dilute barbicide solution for about 10 minutes. Rinse that real good and do several lathers and call it good.
Never had any issues with barbicide on my brushes and that stuff will kill anything.
I don't want to discourage anyone from taking precautions that might be sensible, even if the benefits are perceived rather than actual. After all, feeling good counts too!
But being a scientist, I'd want to know what specific pathogens and viruses we're worried about. And their life spans in the dormant state, and what kills them stone dead. And what the likelihood of encountering them in a brush (or on a razor for heaven's sake) really is.
I've always been fine with coarse brushing (for razors) and lots of detergent (for brushes) plus air and sunlight. If I hear something to give me reason for concern, I'll certainly reconsider!
= Bill