[riddleofsteel]

At no time would a bokken be mistaken for a cane, upside down or otherwise due to its shape and construction. If a samuri carried a bokken it would have been clear it was a weapon. Sword length sections of rattan or cured flexible wood were quite popular with samuri even during the height of the sword era in Japan. They were often used against those who did not have a blade or those seen as beneath drawing your sword to fend off, kill or discipline.
Bo and Jo size staffs where used extensively throughout Asia as walking/hiking sticks. Fighting with these staffs reached the state of a fine art as personified by forms taught in Kenpo Karate and Kung Fu. There are myrid stories of Okinowan Bo and Jo staff practitioners defeating samuri with swords.