And that is false, Kaido said only the strongest one in the world can infuse their CoC in their attacks, implied only the top tiers, make it rare that people can fuse their CoC into attacks, because that it get called "adv haki", since people fuse their CoC into attacks,that make it adv and only the strongest one can use it.
And as I said you people mix up a black CoC clash between two CoC user with the thing what Kaido said and this is terrible wrong. Let me ask you one thing, before Wano, why the black CoC clash happen when actually only CoC user clash? Why we didn' see Black aura leakage when Doffy actually attack Sanji, Law or Guts(with Awakening)? Why we didn't see it with Luffy when he attack his opponent, why it always happen when two CoC user clash each other?
I can answer it for you, because they can't fuse their attacks with CoC, the lightning clash only happen because two CoC user clash each other. The attacks of them aren't get stronger since they can't fuse CoC into their attacks. And we see how it looking like, when even Kaido hit normal people without CoC, we can still see the Black aura leakage. Why we didn't see it from Luffy against non CoC user, why we didn't see it from Mingo?
As I said you guys mixup regular CoC clash with the thing what Kaido said. Only the strongest one in the world can fuse it. Hell Law even didn't know that Luffy had CoC before the clash with Doffy CoC happen. And Law actually see many moves of Luffy, meaning he didn't see any haki releaved power like CoC behind Luffy attack.