There's an idea. The humans just have to get their "boxing" technology. We know the Cylons are very afraid of that, so just put them in the box and pull them out every couple weeks until they talk. Or maybe it could be mimicked with a sensory deprivation chamber.
And do all interrogation in a faraday cage, have them carry in a radio that's turned on so they can see that no transmissions can enter or leave the room.