Chemical pickling, thanks to a gel (Dilunett type from Durieu): devoid of solvent, this gel is applied using a brush with synthetic bristles and the tools are rinsed with water. Then scrape the wood with a spatula.
If this is not enough, in particular to clean all the rough edges of the wood, use a heat gun. You can also make the wood look beautiful by plugging holes and cracks with a quick-drying, easily sanded acrylic wood paste. Always proceed in two passes to fill the deepest gaps.