Self-castration sects attracted up to 100,000 followers across class lines

Evidence

As extreme as self-castrating practices are, the followers of Cybele were not an isolated case. The nineteenth-century Russian Christian sect known as Skoptsy also practiced self-castration. Both men and women did away with their genitalia in an effort to achieve sexual purity and facilitate the second coming of Christ. Although persecuted by the Imperial Russian government, they attracted a sizable following from various social strata, including peasants, nobles, and civil servants. Many were deported to Siberia. Although reliable statistics about Skoptsy followers are hard to come by, judging from the number of arrested members, by the early twentieth century when their decline started, their numbers may have reached as high as 100,000 followers. — Norenzayan, Ara, Big gods - how religion transformed…, 328