Why is "Horse sheath cleaning" trending?

Wikipedia Overview

Sheath cleaning is a hygienic process occasionally needed by male horses, both geldings and stallions, wherein a caretaker, groom or veterinarian checks the horse's sheath, the pocket of skin that protects the penis of the horse when it is not in use for urination. This area may need to be cleaned, starting at a young age after breeding and the birth season, but particularly in geldings. Not only can smegma, a waxy substance that includes dirt and dead skin cells, accumulate, but some geldings may also form a "bean", a hardened ball of smegma inside the sheath or even the urethra that, in extreme cases, can interfere with urine flow. Although a gelding retains the same beneficial microorganisms in the sheath as a stallion, they seem to accumulate smegma and other debris at a higher rate, probably because geldings rarely fully extrude the penis, and thus dirt and smegma build up in the folds of skin. Thus, it is recommended that the sheath be cleaned once or twice a year. Cleaning the sheath is a specialized task requiring a mild cleaner with grease-cutting properties, generally designed specifically for the process, along with warm water and many clean towels. Rubber gloves for the handler are recommended, as the job is rather smelly and messy.