Chastity and orgasm denial discussion

Okay, this might sound like a strange question, but I want to ask it anyway. Also, it may or may not be an issue for me: I am self-locked. My photos show the device I’m wearing, and although I rarely need to remove it for cleaning and shaving, sometimes I do. Once I unlock, my goal is to avoid getting an erection. Obviously, while locked, that’s impossible, but I want to ensure I don’t get hard when it’s off for maintenance. Is this possible? If so, what can I do to prevent hardness?