I think this doesn't really work though (or it does work, but it is very exploitable). If you allow table talk, then you would allow non-spymasters to post a long list of clues the spymaster should give for specific combinations of cards. So I just post a list "if it's these 8 cards, say this, if it's these, say that...." Game over.
So you have to restrict talking. But that is always trouble. I don't think anything other than "all talk is allowed" or "no talk is allowed" is loophole-free.
This is something I had not considered. I think that it would violate the spirit of the game, and such things should be disallowed.
I understand table talk to be conversation between the guessers. In fact, for this to work, there should be no interaction with the spymasters. I would go so far as to say that spymasters are not allowed to post anything but their clues and the results of the guesses. Likewise, guessers cannot post anything to the spymasters. This can be done already today. There's nothing stopping a guesser from telling the spymaster in private message what clue to give for certain words except just plain, old-fashioned good decorum.
So, how about this for the table talk?
* Spymaster is not allowed to say anything aside from clues and guess results.
* Guessers cannot speak to the spymasters, including passive commands like, "If he meant for Ball to be picked, he'll surely say 'dog' next time."
* Guessers can speak to each other about the clues, but the opposite team could glean which words are not theirs, so beware.
Is this loophole-free? Not in the slightest, but it all depends on how much you trust your teammates to not spoil the fun. There are a lot of games on here that rely on trust.