I might think waiting for all the odor to be gone is not the way I would go as some wood does have a smell even when just wet from rain. My method is to do a bleach soak to clear anything that might already be on the wood like bugs, worm, fungus or just anything that I don't know about, so I don't want to move unknowns into my tanks----just because.
So if you have a large enough container like a plastic trash can, I recommend sticking it in there, cover with water and weight it down if you find it floats. Rocks are handy and cheap for me but whatever it takes? Add like a 1/2 cup or so of plain cheap bleach with no scents or colors added as we don't want those "unknowns" and let it set for at least a day so that the bleach has time to totally soak into any little spaces in the wood where things might hide. Watch not to get the bleach water on clothing as it will bleach them or make holes!
When you find the wood no longer floats, take it out and set it someplace to dry and let the chlorine gas off. When you no longer get the chlorine smell, it is good to go in the tank.
But if you want to speed the sinking up a bunch, I like to screw pieces of tile to wood as weight and it also lets me choose what angle it sets with the flat base. Quicker and I get more choices. I do often scrape off any soft parts to avoid them coming loose to have to chase them around the tank.
Many will try to scare you about bleach but it is just chlorine mixed in a bottle and stronger than the amount in drinking water, so we deal with it the same way and let it gas off. You smell it around a pool as it gasses off and it does the same with our wood, just give it plenty of time to lose the smell!