Yes, it's true. You can get that item in FF4j and FFIV PSX. Square seems to like having some hints to dirty magazines, as there's references to them in FFV, FF6j, FFVIII and Seiken Densetsu 3. The porn magazine has no uses in the game, though if you use it as an item on the field, the character sprite you're currently controlling looks around to make sure nobody is watching you read the magazine.
Then the screen goes purple and Dancing Calbrena music begins to play, and Cecil says "Whoa! I'll go blind!" That's about it. I like using it just before the final battle against Zeromus. You know, everyone is mentally preparing themselves for the last battle to save the world, and as a true Paladin, Cecil prepares himself by... opening up a porn magazine!