Good news: These things are salvageable!
I let it sit in the dip for bout an hour and it was still stuck tight so I ran it under hot water for a couple minutes and then just started forcing it open and closed. Did that bout 10-15 times and the rust/buildup that was keeping it stuck finally gave. It is opening and closing pretty smoothly now. I will prob get it nice and cleaned up and use some white lithium grease or or the like to keep it from getting stuck again.