Ha! Ha! Ha!

...but I keep hearing it was 'banned for drug use' but can find no evidence of such ban.

In any case, people have used laughing gas recreationally since its discovery over 200 years ago. It's rapid effects and rapid dissipation along with relatively low toxicity keep it popular.

The use of rotoscoping, a technique for 'tracing' live action, pen & ink ad the admixture of photographic and animation mixed in the beginning and end of the film is unusual.

Max and Tex Avery were both noted for their utter disregard for 'reality' realizing and frequently stating that you 'can do anything in a cartoon.'

Animated animals, plants and objects permit a cartoonist to say things about society which might otherwise go unheard due to immediate recognition and reaction by prejudice.