Depending on the length of time you're planning on wearing it, the answer varies. If you're only wearing the chastity device for one bedroom session, then silicone is perfectly fine! However, if you'll be wearing them long term, you're better off going with metal. Wearing a silicone chastity device for too long, even with frequent cleaning, can lead to chafing, fungal infections, lesions, and cause the silicone to start smelling a bit funky.