Thomas Merton is popular among those of new age followers, modernists and those who who don't know better.
Cardinal Ratzinger wrote about the same thing Fr. Hardon speaks of. Channeling is just one of those false teachings spread by those who are not obedient to the teachings of the Church.
Fr. Hardon's cause is up in Rome, and he speaks honestly and knowledgeably regarding "Charismatics today". Many of the Spanish speaking are heavily in this "charismastic" sect.