How can the mythomaniacs be described?

Roger Lhomoy (1904-1974) was a fantasist who failed to prove any of his claims.

The “Knights Templar” at the Château du Bézu was a hypothesis put forward by Abbé Maurice-René Mazières during the 1950s. Abbé Mazières later co-wrote a book with Abbé Bruno de Monts debunking the myth of the “treasure” of Rennes-le-Château.

Despite all this being total bunkum for literally decades, the Believers keep uncritically repeating it.