TC, at some point you have to let BR make his own mistakes. He's not going to listen to you, he's dead set on following Delora and the more you attempt to drive a wedge between them the more they feel they need to stick together to fight against the "haters".
If her drinking drain solution in the bathroom to threaten suicide didn't wake him up to how manipulative she is, reasonable conversation and evidence will do nothing. Stop trying to help him, he needs to decide on his own and maybe hopefully everyone is wrong and their marriage will be fine and happy. If not well, he was told warned. He can dig himself out of the hole and go back to Ohio.
Anything helpful you're doing is going to be turned and twisted into something else. Sometimes just gotta let someone eat shit before they realize they don't like it.
He's literally repeating past mistakes now, and he was just starting to get better. Letting him eat shit's like letting someone with Pica eat bricks.