Male chastity consists of many types of controls. There are the standard cock cages for sexual and masturbation denial. The are devices for milking so the slave or male chastity man is at least cleaned of excess semen. There are many other male chastity devices for training but there are also device for punishment. Cock and Ball crushers fall into that category. There must be punishment to make forced male chastity work along with humiliation. I have found the cock crushing and ball crushing are very effective forms of punishment when used on male chastity slaves. After and intense session they are no longer interested in having sex. To humiliate my slaves more at times I will have another man or a women wearing a strap-on fuck the slave who is being crushed. I have included a picture of a ball crusher to give you an idea of how it works. You need to work slowly with these devices because pain is the idea but not permanent damage. Male masters should try using these items on themselves to familiarize themselves with how to inflict the correct amount of pressure.
See this and many other devices at koalaswim.com
See how the balls butterfly out when crushed.