Agree. The degree to which it will put out tannins and color the water varies with different types of wood and different individual pieces. I've got a piece of one of those dark bogwoods that's been soaking for three months now, with periodic dousings with boiling water on the weekend when I have time. I just put it in one of those large plasic box things they make for storage and keep it submerged when I'm not giving it a boiling treatment. The yellow is taking longer and longer to come out of the wood now.
It does put you ahead to have really dried out wood rather than anything new enough to still have sap or bark. If it really looked like driftwood you should be doing well. Sometimes driftwood will sink after getting completely soaked but sometimes it needs help weighting it down.
~~waterdrop~~