Generally, there are two types of driftwood: Sinking and Floating.
A typical Malaysian driftwood is dense and generally does not float upon initial use. Aquarium aquascape or aquarium driftwood designer like to use dense driftwood is because it can sink directly. So they don’t have to do extra work to make it sink.
Floating driftwood can not sink immediately is because of the lower density from the wood. It is still popular used by hobbyist because of the shape although it cannot sink immediately. The cons of floating driftwood is easily rotten & broken after a short period.
For the driftwood that cannot sink immediately, hobbyist or aquascaper will use several method to keep driftwood from floating, such as: tie it, glue it, soak it or boil it/soak it. It depends on what equipment you have on hand and convenient to you.
So which driftwood is suitable for your aquarium? It’s on your choice. 🙂