Stated by who??
Roger and prime beard used it first and nobody knew what it was ( there was leaking haki)
Then kaido used it second on screen to KO luffy
Then luffy got up and explained to us the reader that it’s coating ones self in coc
Lol I doubt we are reading the same manga
Everytime shown on screen advcoc has had leaking haki
Oda himself said in the SBS that Odens attack against Kaido had advanced CoC in it. This indicates some things:
1. You need advanced CoC to even be able to scar kaido.
2. Zoro also used advanced CoC, since you need advanced CoC to permanently damage Kaido.
3. Odens attack at least in the manga didn't show the same display like WB and Roger, but still was stated to be infused with advanced CoC.
Kaido says that the scabbards attacks were too shallow and luffy himself said that his attacks with ryou were to shallow.
Which indicates that Ryou alone cannot damage Kaido permanentely and therefore scar him. The only ingridient for this is advanced CoC.
And since you need it for Kaido, Zoro also used it.