As far as the actual machines themselves....
Heres a BLUE PETER DIY version...(Dont do this as a disco...you'll get laughed at terribly)
1) Get one of those socks that your worst Grandma gave you for Christmas.
2) Spray shaving foam non-stop into the open end of the sock
3) Hold the can of shaving foam (still spewing foam) AND the sock infront of a fan
as the foam oozes out of the tiny holes in the socks materials the tiny oozles of foam will be caught in the draught from the fan, and...
4) Hey Presto....thousands of little "flakes" of foam drifting around.
The difference is...the foam wont disolve harmlessly away after a few minutes of contact with a warm, dry floor. Even the proper snow fluid will stay around for a couple of days if spread thickly on wet ground on a cold day...I did my front garden with two Antari S-100 snow machines a couple of years back... I couldnt do it this year, as both the pumps have failed and Antari dont carry replacements any more. Too noisy an effect for me to thing about using on the Disco again - the fan noise, even on the "LO" setting was an atmosphere killer - good for renting to local councils for horrendous amounts of loot, for Christmas light switch ons though.