During his day job ace archeologist "Indiana Jones" commands students' attention with a classroom textbook. But it's the explosive, gunshot crack of Indy's whip that keeps his enemies in line on his daring adventures.

"Most people have no clue what kind of a killer weapon the bullwhip is or how hard it is to use," says Anthony De Longis, Harrison Ford's personal bullwhip trainer on "Indiana Jones and the Kingdom of The Crystal Skull."

Designed centuries ago to motivate creatures bigger and stronger than humans De Longis says, "The whip was man's first supersonic tool. The tip and the velocity it achieves will rip you open like a knife."

De Longis began tutoring Harrison Ford with a simple plan. First he taught the star, much like he did Michelle Pfeiffer on "Batman Returns," that a whip is a 700-mile-an-hour weapon. As De Longis says, "It goes fast so you don't have to. But use it improperly and this tool will turn on you, usually when it's the least opportune."

Whip it good! Harrison Ford's training secrets on 'Indy 4' revealed

Second he showed Ford the basics of his "rolling loop style" whip method, which the self-taught veteran of 35 years developed.

"Essentially what I'm doing is putting my loop on top. When the whip forms a loop it is aligned with itself. That's when it is most efficient," says De Longis.

It's a very different approach to traditional bullwhip training, which De Longis says, "Is too hard. Your arm does all the work and you're dragging the whip in and out of frame. It really becomes all about the whip, not the character."

Watch Pfeiffer flick her whip around Christopher Walken's throat in "Batman Returns" and audiences can imagine how Ford might use his legendary whip to reflect Indy's character.

"Michelle understood what I was offering her character," says De Longis. "The way she used the whip had to be hypnotic, alluring and at the same time full of danger. Harrison got it, too. The whip must reflect the inventiveness and intelligence of 'Indiana Jones'' character."

Snappy finish: 'Indiana Jones' revives Hollywood's love of the bullwhip

Growing up in the 1950s, bullwhip kings like Zorro and Lash LaRue were huge inspirations for De Longis. But it was seeing "Zorro, the Gay Blade," the 1981 comedy, that inspired him to master the bullwhip.

"Before 'Raiders of the Lost Ark' there hadn't been any great whip work since Douglas Fairbanks senior in 'The Mark of Zorro' in 1920 and 'Don Q Son of Zorro' in 1925,' says De Longis. "But 'Raiders' inspired a resurgence of the bullwhip in Hollywood."

De Longis has not seen "The Crystal Skull" yet. But sources tell him Ford's work was full of Indy flare.

"So much secrecy surrounded this movie. All I was privy to was what Harrison told me," says De Longis, who worked with the actor two to three days a week for two months before shooting began. "Harrison orchestrated the bullwhip scenes himself and did an excellent job."

As De Longis says, "The bullwhip is the perfect accessory for 'Indiana Jones' because it's 5,000 years old. I was hoping Steven Spielberg would show Indy unearthing a hieroglyphic of a whip," he laughs. "It didn't happen. Maybe in the next film, if there is one."