Why do people use a venik (birch branch bundle) in Russian banya steam baths?
Before entering the steam room of a Russian banya, people soak a venik, a leafy bundle of birch or oak branches, in water. Once the body has warmed up, the venik is used to tap or stroke over the shoulders and back. Water is poured onto hot stones to create a humid cloud of steam, and inside that steam, the venik becomes a tool used on the body.
Guides to the Russian banya describe both the way steam is made by pouring water onto stones and the way the branch bundle is used after the body has warmed.