That is not the only warning film not to do it because people were dying all the time: https://archive.org/details/more_dangerous_then_dynamite
Some headlines of people making the worst mistake of their shortened lives:
https://www.newspapers.com/article/wilkes-barre-times-leader-explosion-caus/13045180/
https://post-gazette.newspapers.com/article/the-pittsburgh-press-gasoline-caused-two/91356754/
Occasionally, they got lucky and survived.
https://www.newspapers.com/article/hot-springs-weekly-star-cleaning-clothes/124927252/
https://www.spokesman.com/stories/2017/aug/29/100-years-ago-today-in-spokane-woman-using-gasolin/
Reminds me of the old school experiment where you dissolve a tooth in a glass of Coca-Cola.