You know the world has taken some profoundly weird twists when the phrase “weapons-grade confetti” makes perfect sense.

I think it gets funnier if he’s literally just saying clap each time because the gloves are getting in the way.

Mustard’s umbrella includes a rocket mode which let her jump over a two-story building from a standing start, which is tiny enough to be concealable, sturdy enough to work just fine moments after being shot full of weapons-grade confetti from an unexpected direction, and she’s been able to keep it maintained while out on her own, without routine access to the official lab.
The Shadow Circus, meanwhile, appears to have access to all Clown Corps tech (or at least everything the Corps had prior to the PSC raid), plus non-pie teleportation, implying significant in-house engineering resources. Seems to me that glowing hammer probably involved some sort of momentum-manipulating power assist.

They’re not clowns. They are the entire circus.

Whatever the flail’s material properties, knocking multiple other people off their feet and drag them around the room while maintaining your own balance is implausible. Luckily, the physics in this setting are somewhere between Looney Tune and street-level superhero.

He’s not pushing new boundaries in clown goondom. He’s just clowning around.

Hammer-throwing is a real Olympic sport, so this isn’t out of the realm of possibility (especially if the flail has some future-tech making it lighter than it looks). You can move some pretty heavy stuff pretty fast with the right leverage.