Fun and abundant drug with minimal long or short term health consequences: exists
Terf Island: oi bruv, ya got a loiscense for that squiree cream product do ya? ya can't ave that mate, ya migh en up feelin good withou ettin propuh consent from the king!
It says they'll make exceptions for legitimate uses, I assume that includes making whipped cream. It'll probably just be much harder to legally get your hands on it unless you run a catering company or restaurant.
CO2 would cause the cream to sour as a result of it's acidity, and plain nitrogen isn't soluble enough, so it's probably not very easily replaced.