DMing the Bible: Table Talk

Introduction:
Though this series not intended to be a verse by verse commentary, this third installment will focus on the third chapter in Genesis. In the first two chapters the world and all its fullness was created. The human species received gender and gave us our first cast of characters. Chapter three continues the distinctive j-source narrative as it explains why humans live in the desert instead of the lush garden setting for which God had created us.
The Text:
The first verse of chapter three introduces one further character, the serpent. The word used here is really garden variety snake, but in the Ancient Near East (ANE) the snake was viewed as a creature of supernatural quality. Because a snake will from time to time shed its skin and appear rejuvenated, they were believed to be immortal. Let's take a minute to talk about the serpent as it functions in this tale. I believe if we are to take this tale as a proto-"just so story," it would be inappropriate to draw the character of the serpent out as an allegorical figure. This is simply a character in a fable, and in the rest of our lives we do not need to identify talking animals in fables as agents or personifications of evil. The serpent approaches the woman and engages her in a conversation about the tree of the knowledge of Good and Evil
In Genesis 2:16-17, God explains to the human creature that the fruit of the tree of the knowledge of good and evil is off limits for eating. By the time Eve and the serpent discuss the fruit of said tree, she has constructed a second layer of defensive legislation that prohibits not just eating the fruit of the tree but also touching it. The serpent suggest that it is not true that eating the fruit will kill you, but that the reason God gave humanity this rule is to keep you from being like gods yourself. Indeed Eve eats the fruit and gives some to Adam who also eats (though without first debating the question as Eve had done), and it turns out that they didn't die. The realized all kinds of things about themselves and their situation.
God, in the habit of walking in the garden, finds the people and gets Adam to tattle on Eve. In the punishment phase of the trial God makes the world as people living in the ANE would find very familiar: snakes slither about and engender fear and loathing from people, pregnancy is difficult and dangerous for mother and child, the genders are not equal, and agriculture is difficult and thankless. As a kicker at the end of the story we discover that the knowledge of good and evil did make humanity like the gods, to protect them from immortality, God must send them away from the garden. And that's a story about why the world is the way it is.
The Game:
If this story were a game session, the plot places PC's (Adam and Eve) in a position where through conversation they must decide between competing claims of two NPC's. As a DM, I love running this kind of session. I enjoy the side of D&D that encourages people to think through problems and decide upon courses of action. This kind of play demands that people stay more or less in character during play; it certainly means that players need to avoid "table talk."
I define table talk thusly: conversation that sounds like it might just be happening in character. For example anything that would prompt a DM to exclaim "Did you really say THAT?!?!?" or "You did WHAT??" is probably table talk. Here are some solutions.

1. Character "voice":The group with whom I play includes only one or two players routinely use an alternate voice for their characters, and so they have fairly adroitly avoided having jokes the make wind up in the mouths of their characters. This doesn't mean of course everybody has to play with crazy accents or affected speech impediments, but it may mean that a character may have a particular phrase that only gets used in character particularly at the head of a dialogue block.
2. The White Flag: My husband, Carson, is the most likely of our group to wander afoul of table talk. He likes to play out alternatives to the scene during the session (alternatives that would probably have horrible horrible consequences). Our group has basically agreed to let Carson say whatever he wants, with the knowledge that it will be counted as "in-character" unless he holds aloft a piece of white paper set aside just for this task. Whatever Carson says when the paper is up doesn't count. This is a rule that we only apply to one person, but it works for us given the nature of the group.