SAN FRANCISCO - "Nacho Libre" director Jared Hess gained the Spanish skills he needed to shoot the Mexican-wrestler comedy in Mexico with a local crew by spending two years as a Mormon missionary in Venezuela.

Except for star Jack Black, the movie features an all-Mexican cast, including telenovela star Ana de la Reguera as Nacho's love interest, and real-life wrestlers Bronco, El Pony and the midget tag team Satan's Helpers. It was filmed in and around Oaxaca.

"These are real people you could never find in Hollywood," Hess told the San Francisco Chronicle in Sunday's editions. "We did all the casting in Mexico City and on location because it was very important to me that we be authentic to this outrageous Lucha Libre world."

Hess attended as many Mexican wrestling matches as possible while developing the "Nacho" story with his wife and collaborator, Jerusha, and Black's producing partner, Mike White.

"It's one of the most politically incorrect things you'll ever see, and it's very therapeutic," Hess said. "The crowd totally trashes luchadores they don't like, and there's always this banter between the wrestlers in the ring and the people in the crowd."

Hess' interest in the sport came from watching films of Santo, Mexico's most famous luchadore, on late-night television when he was growing up in Idaho. Before long, he was filming wrestling matches between his siblings in his backyard.