In what move do fighters dip their hands in glass?

Fighters dip their hands in glass as part of a traditional ritual in the martial art known as "Kalaripayattu." This practice is intended to toughen the skin and prepare the fighters for combat. It is often associated with extreme forms of training and is not common in modern Martial Arts or combat sports due to safety concerns. The use of glass can lead to serious injuries, and many practitioners today opt for safer methods of hand conditioning.