They already talked about how they would "question" him while they waited for him to wake up, so they exactly wanted to start how they planned it.
First was the classic waterboarding and fingernail pulling, and if that doesn't work, then the tooth pulling. If that too does not seem to work, then they start off with the bleach, slowly pouring it into some of his wounds, and the indescribable pain will cause him to talk.
If those didn't work too, then Benjamin would start with the scalpel, slowly cutting some fine lines into Marco's skin or maybe popping out one of his eyes until he says everything they want to know at least that was the plan but there was somebody inside who didn't want to exactly do these things, at least at first.
As Benjamin and Thomas picked up the water and the towel, Linda too got up. "I'll do it first." She said, and the both of them seemed a little concerned and at the same time sad, they really wanted to do it.