He's aware he has the power to coat his sword, otherwise it make no sense for him to able to only coat Sandai Kitetsu all the way back in while the other two swords weren't. Only someone with control over their haki can do so.
The current acoc is nothing more than the same coa coating technique, but applied to coc.
He thought he was just applying his coa, but enma sucked out his coc as well with his awareness.
It sucks? Yes, just like enma, but it is what it is.