Скачать или смотреть The liquid used for soaking is tung oil.

Soaking the finished wooden frame of a mazha (folding stool) in tung oil serves the following main purposes:

Wood Protection: Tung oil penetrates deep into the wood, filling its tiny pores and forming a protective film. This barrier blocks external moisture and air from contacting the wood, preventing it from warping, cracking, or deforming due to moisture. It also reduces color fading caused by oxidation, extending the mazha's service life.
Performance Enhancement: After soaking in tung oil, the wood's toughness and strength are improved, making the mazha's wooden frame more robust. It can bear heavier weights, resist damage, and become more durable.
Corrosion and Insect Resistance: Tung oil has anti-corrosion and insect-repellent properties. It inhibits the growth of microorganisms in the wood to prevent decay while repelling pests, reducing the risk of insect infestation and maintaining the frame's integrity.
Aesthetic Enhancement: Tung oil gives the wood a warm, natural sheen, enhancing the mazha's wooden frame with a beautiful, organic texture and unique charm. This improves the overall quality and visual appeal of the mazha.