Yes, but it's a considerable amount of effort to have multiple characters ready plus having supplies and gear for it. I know it's not hard to have legendary gear on ~10 characters, but it still requires a good amount of management for "only" a increased chance at getting into the thanatos room.
After all none of their characters might get chosen by the RNG system and Genesis opposes to the idea of a ip restriction to allow people in internet cafes to also have a chance.
Also I think having a 4 digit passcode randomly generated wont help much, because it makes it even more likely for bots to get in since they can generate and type all permutations faster.