Can urethral play be done safely?

Patient: Suggested category name: Sexual practicesI have read a lot of first-hand accounts of the pleasures to be had via urethral play, which is the insertion of objects (dilators, sounds and other assorted off-label instruments) into the male or female urethra for the purpose of sexual pleasure. Many of these “resources” discuss the precautions to be used (need for clean, sterile conditions, how to or not to insert said object, etc. to avoid injury and infection). Full disclosure: this is something I engaged in regularly when I was a curious teen, and it was definitely a pleasurable activity, and due to sheer luck, I never had an infection from it. The question therefore: Can this activity be done safely, and if so, how? My belief is that if people are going to explore this anyway, it would be better to have sound (pardon the pun) medical advice on how to minimize risks, rather than simply telling people not to do it. Thanks!