Speaking of dispersing crowds, I always thought that in cold climates a very effective and simple tool when it's cold out is to use, essentially, high pressure garden hoses spraying streams of chilled or ice water.
Something that we wish that the police would use during the anarchist demonstration at the presidential palace during our Independence Day (December 6th) celebrations every year.

You and me both, you and me both... Maybe they'll wise up and get one of
these there this year...

When you absolutely, positively must wash 32 tons of laundry in an hour....