Rearranging the letters of 'Holy Grail's certain' gives:
Really? Go, Christian!
(by Aronas Pinchas ) (2010) (pending approval)
Search it, nail glory.
(by Aronas Pinchas ) (2010) (pending approval)
A clear Glory in this.
(by Aronas Pinchas ) (2010) (pending approval)
Only Christ-regalia.
(by Aronas Pinchas ) (2010) (pending approval)
In allegory - 'A Christ'
(by Aronas Pinchas ) (2010) (pending approval)
Other related anagrams without their own page:
"Experts Claim They've Found the Holy Grail in Spanish Basilica" -> "Golden chalice in Holy man's very Last Supper? Exhibit is a Faith!" (by Aronas Pinchas ) (2014) (pending approval)
"The Holy Blood and the Holy Grail" -> "Ah no, I hardly get hot. Bloody hell!" (by Stanley Accrington by hand) (2006)