brena,
You are allowed by the mods to post a question & I'm equally allowed to reply. Whilst my reply was 'to the point' - there was nothing wrong with it.
If you don't want to use it on board - stick it in the checked in baggage.
- Though I concur that getting a bunch of face masks will do the job you want just as well if not better - I'm bemused how hanging an air purifier around your neck helps with breathing in...? (Having searched online I'm tempted to suggest mumbo-jumbo rather than scientific basis...)
I think there are people who post questions looking for only the answer they want to hear - not the answer that is useful.
And as an aside - we live in an age where people thinking asking means they have a right to receive.