The main thing is that the people giving hints don't see the situation from the other side – they should be hit with a candelabra for that.

Of course, we will punish particularly malicious hint-givers, but it's impossible to keep track of every little hint, so I don't see the point in banning them altogether.

We're relying on the players and guests to be decent. Because it's really impossible to fight this.

Otherwise, let them give hints; it's part of the communication (especially if it's in the form of teasing), and it can also improve skills – the opponent can also learn something interesting from the nature of the hints.

The players will be sitting quite far apart, so the opponent won't hear anything. But if, say, a couple of top players are standing around one, chatting, while the other doesn't have any of these top players... then it will be tough for him.
Okay, let's see how it goes. Don't count on me too much; I haven't played VT much. I'm in charge of organizational matters, meeting guests, and arranging their accommodation and leisure activities.