To essentially wipe the mind of all sane
thought (and likely replacing with insane
thought, though not necessarily so), presumably from an encounter with something so incredibly insane as to have the
power to do so.
This process is similar to sanitizing, but instead of removing dirt and/or germs, it removes rationale; thus, insanitize is an effective portmanteau of the words insane and sanitize.
"Don't pay attention to what he says, or he'll insanitize you with his stupidity."
{origin of phrase}
"So I was having a discussion with My
Mother. The rest of the details are unimportant,
logic and reason are the exclusive domain of the man." "Whut, what prompted this? Did I miss some epic fucktardation or something?" "
Yes, yes you did. Be glad you didn't see it originally. This mirror alone will surely insanitize you."