Here’s the comic book-styled theater herald for Black Belt Jones. The following anecdote comes from bmovievault and mutantreviewers:

“One of the most memorable production stories involves fight coordinator Bob Wall, who had worked with Kelly on Enter the Dragon. During filming, Wall noticed that Kelly was allowing his kicks and punches to actually connect with other actors, risking and sometimes causing real injuries. To correct this dangerous habit, Wall paired Kelly in a scene with black belt heavyweight Jim Bottoms, who bluntly informed the movie newcomer that “he would tear off his head” if Kelly forgot to pull his punches. This intervention worked, and the remainder of the shoot continued without incident.

“The film’s climax featured the now-infamous car wash battle sequence, where Jones fights through knee-high soap suds. This sudsy showdown included one of Kelly’s most visually striking moments: a chain of butterfly kicks that took out four consecutive henchmen.”