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."