Just a stab in the dark here, are both babies head down? I just wrote about this on another post, but I had a similar problem. Both babes were head down, A was posterior and B was facing A. It was like they were hugging upside down. Cute, but it was a problem because the chin of Baby B prevented the shoulder of Baby A descending. So like you, no pressure on the cervix, no descent, etc.
What I ended up doing was (castor oil) but also sitting on the birthing stool and having an assistant hold Baby B from the out side. Mine was done in the context of pushing, but I think you could do the same at home. Sit somewhere like a birthing ball, toilet, where ever and hold Baby B in a way that might let Baby A drop. Or maybe hold Baby B while walking if that's even possible.
FWIW - I think you and I had the same midwife, although her back-up ended up catching my babes. The back-up (so amazingly awesome!) says she has more problems with the vertex-vertex position than any other because of this.
Just an idea. Hope things get moving soon!