of the pine wood.
so, for cleaning the wood don't use any wet product , because the wood base would absorb the liquid ! just use a soft brush to remove the dust.
if you want to protect more the wood base , you can apply a natural wax ( bee-wax) or paint it with a transparent paint, but take into account that any finishing you would apply on the wood will make it darker.
please note : natural pine wood goes darker as well as it's exposed to sunlight for a long time. if this happens, you can sand the surface of the wood to make it back to light , original 