Yes it can, all it is is Zoro going all-out with his Haki at all times.
It's proved by Zoro's two other swords smoking as well as Enma. Someone show me the panel stating Enma has the ability to transfer its powers to other swords.
Enma is what allowed Zoro to realise Oden didn't regulate his Haki, that's all. Other characters don't do it because of the same reason Zoro didn't do it prior to Enma - he thought if he did it he'd die.
It's like Luffy deciding he needs to be in permanent G4. It would never occur to him that it's even possible so why would he ever try? Plus I doubt every character can do it - you need to be capable of sustaining a high release state which is something your body needs to adjust to over time. Oden perfected this state and Zoro will too eventually, but I guarantee his time-limit on KOH has already increased.