HooKooDooKu
Aquarium Advice FINatic
My only worry is that it will float even after I soak it for a while.. Guess I could screw it to some shall I'll have to find some stainless screws tho
The boiling process will help to saturate the wood quickly. Once saturated, it will either sink or be just about neutrally buoyant. Should it be closer to neutrally buoyant, it shouldn't take much weight to hold it down.
I've found brass wood screws work well.