It depends on what the goal is. If you want to feed them information, you
leave them in place and presumably unawares. If you want to exploit them,
then interaction is needed. Doubling is almost impossible without letting
them know what you know. There's also purposefully incorrectly IDing them,
and keeping them out of meetings. It depends on what the game is, who the
players are and how they define their endgame.
Yes, getting the state to subsidize and sponsor meetings is a great idea.
Трест exploited it like few in recent history have been able to.