The Japanese use a tool called Uzukuri to burnish the wood, to make the hard
wood shine, and rub away some of the softer summer wood.
This technique is used for external siding, Sugi (cypress) wood first charred,
then rubbed to make the surface shine.  This is called 'shou sugi ban.'  It
reduces the vulnerability to insects.
It is also commonly used on the Koto (Japanese zither), made of Paulownia,
classified as a hardwood, a lightweight cypress, but with properties light like
balsa and soft like cedar.  Again, the surface is first charred, then rubbed.  
https://youtu.be/0w2HmGVq2DA?si=aaJCIe_yaaiYi8AV

The technique is also used for interior furnishing and paneling.

The Uzukuri can be purchased in three grades, from coarse and stiff to soft. 
The stiff ones are made of reeds, while the intermediate and soft from Tampico
and horsehair.
Here is a link to see the tool in 3 grades.
https://hiraide-sanjo.com/photo/album/1014757/page/4

Here is a link to a Kyoto based carpenter that teaches woodworking in English.
https://www.facebook.com/story.php/?id=100018912470740&story_fbid=12452932392174
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