bamboo is cooked in the drum is for the purpose of making bamboo durable, this is the right way to make durable bamboo.
What is meant by traditional preservation, here is a practice and a particular treatment on bamboo which is a hereditary condition which aims to improve the life of bamboo.
Various ways of preservation include:
Control timing.
It is the timing of bamboo harvesting at certain moments which, according to community beliefs or habits, can increase the durability of bamboo compared to logging at any time.