Birching is a form of corporal punishment with a birch rod, typically used to strike the recipient's bare buttocks, although occasionally the back and/or shoulders.
Birching of a prison inmate during interrogation; The Netherlands, 17th century
A magistrate's committal for birching of two children dated 4 December 1899 displayed in West Midlands Police Museum, Sparkhill, Birmingham, England
Birching in a women's prison, US (c. 1890)
1839 caricature by George Cruikshank of a school flogging
A switch is a thin, flexible twig from a tree or shrub used as an implement in corporal punishment. The application of a switch is called switching.
Birching
…often softened by keeping them in hot water prior to use. Being struck by the twigs induces a pleasant stinging sensation and very little actual pain. Switching Birching at World Corporal Punishment Research…
Switch in Adam Johann Braun's Maedchenschule, 1789
L'Exécution de la Punition de Fouet by Jean Baptiste Debret