The film is based on a short film with the same title.
The sauna seen at the film was real and working. It was located next from the place where the film crew were staying. The film crew also used the sauna actively on their free time.
Character Mise mis-spells various times "trunk" as "drunk". He also misspells the "prick" as "brick". These were accidents by Mise's Finnish actor Jari Manninen. The director liked the misspells though and felt it brings more for the character. So after the first misspells the director wanted Jari to keep on saying it as wrong way.
The only lines that can be heard in the original Bunny the Killer Thing short film and in the feature film are "Fresh Pussy", "Pussy" and "Who's Gotta Bigga Digga?". All of those lines are said by Bunny the Killer Thing.
Character Vincent's line "I like you from here to Helsinki" was improvised. The line eventually can be heard as off the screen dialogue.