Twelve actors were used as body doubles in various scenes for the Jonnie personas including cinematographer/co-writer Domenico Grasso, his wife/ producer Melanie Grasso, actress Erika Ishii (Elaine) and several other cast members. The main body double was actor/assistant director Mike Nicholas.
The body doubles standing in for the other personalities would often make faces and grab their nipples in an attempt to make Jonnie Stapleton break. This worked many times.
During the living room fight sequence between Jack and Boris, the body double (as Boris) who lands on the coffee table breaking it in half is the cinematographer/co-writer Domenico Grasso. He wore his steady-cam vest underneath Boris's sweater to protect his back during the stunt.
Due to the film's tight budget, many of the stunts in the living room fight sequence between Jack and Boris involving break-away glass and tables had to be done in a single take.
Most of the effects used for creating the illusion of the same person on screen multiple times was done using split screen as opposed to green screen. In the end of production, only 5 green screen shots were used in the entire film.