Haven't tried it, but I imagine the method where you tie 3 pieces together into a chimney would be the most efficient and could be done with just a small fire. https://japanwoodcraftassociation.com/traditions/techniques/yakisugi-shou-sugi-ban/
I've seen videos of folk doing it this way.
@Howard started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Haven't tried it, but I imagine the method where you tie 3 pieces together into a chimney would be the most efficient and could be done with just a small fire. https://japanwoodcraftassociation.com/traditions/techniques/yakisugi-shou-sugi-ban/