As long as you clean off the ash at the end I couldn’t see any issue with it, give it a light buffing to knock off any rough/loose bits and then wash them off to not stain yourself or clothes. assuming you don’t accidentally go through all of the finish it’s fine, but if you do it’s easy to make again. It does improve grip on things as well so depending on the type of furniture it might be weird, but what’s the harm in testing?
Recently I tried somethingon my garden beds I used on my hammers for a few years, basically I burned the wood, scrapped off the excess char, rubbed on a coat of boiled linseed oil, burned it again and repeated 2 or 3 times. I was told that was how they made the black stave churches in Europe but have looked into it and it’s not quite what they did. It leaves the wood black obviously but it lasts longer than paint( I’m not planning to touch it again for 5 years and even then likely won’t replace anything), and looks way nicer in my opinion.
I had not heard that term but yes you are right, thank you! I knew it was taken from a older technique by my brother and modified for my use now I know the origin!