I suspect that Penn and Teller, James Randi or any competent magician could become a saint by fooling the gullible or self-deluded fairytale believers among us.
do they know they have to die first?
It doesn't work.
Such is the animus toward the Catholic Church that if it were possible to embarrass the Church in this way, someone would already have done it, including some of those whom you mention. Penn Jillette in particular, has distinguished himself by his outbursts against the Catholic Church.
Contrary to popular belief, the road to sainthood is long and exacting and the gullible are not those who accept the Catholic Church's judgements in these matters, but rather those who fall for the recycled, centuries-old schtick of conjurers, shamans and magicians.