Difficulties with wearing a device? discussion

Hello, I’ve been wearing a chastity device intermittently since 2009. I’ll post a more formal introduction in the next few days. For now, my main question is about locking mechanisms. What options are there for one that isn’t so simple to open without possessing the right key? I tried out inexpensive models and the HT3 variant, but they all seem to yield with just some metal tool. I was hoping for a magic lock because I struggled to remove my device otherwise. A standard padlock could be snipped. Any suggestions?