(and a preemptive defense of my substantiveness here: This is one of the exact arguments used by the fascists (aka autocratic authoritarians if you're triggered by the F-word) as if it might constitute a serious argument in an open society based around individual liberty. It is important that we resoundingly mock it)
Just call them what they are: totalitarian-authoritarian personalities, whose roots lie deep in the desire to be free of the perceived "filth of others".
These personalities aren't the real human being - they're a facade created by the human to shield themselves from 'infection'. The totalitarian-authoritarian personality is a meme which can be triggered in, basically, any human being.
What triggers it, will also un-trigger it. Keep flinging filth at them until they wake up from their totalitarian stupor. Fling their own filth at them. Show them this website, let them know they are being tracked by the "Truly Clean™", and that - one day, when they start respecting human rights - they will be treated to nice, clean, freshly laundered and steam-pressed human rights, also.