I have done some spruce.Done in a convection oven at 385 F.
The bracing gives a color comparison. A six string uke I need to finish.
I put the wood in the oven and step the temperature up to 250, then 350, first to dry out the wood then to soak the oven to equalize the temperature. Then I go to 385, about an hour should do. Gasses given off when baking and the smell of the wood is still prevalent the next time the oven is being used. I put a layer of aluminum sheet on a lower rack so that any radiation does not raise the exposed wood surface to a higher temperature than the other side. Not much else to add, I do have faith in my temperature display, 385 is about at the bottom of efficient treatment, lower not much happens and higher there is a danger of lighting something up. Not a bad idea to do a practice run first.