Week after week, I see WC groups with maybe 1 or 2 people who are new (achievement after the clear), yet those same groups end up with 5+ players getting assimilated on Ozma, and stepping into 5+ garrote traps on hair lady.

Stop freeing them. It's the only way they're going to learn that they can, and are supposed to, avoid those mechanics. I can't think of any other reason why a player, doing the same fights over and over again, can't figure out how the mechanics work, unless they have a misunderstanding of how they work.

Stop freeing people from Gaols.
Stop freeing people from garrote traps.
Let them learn.