I love the chastity but me and my partner would love it i didn't get any erections at all it would add to the humiliation. I don't think there is any anti-errection pill or anything available. I have tried numing cream but not strong enough.
An anti-erection pill would be great, but as far as I know only hormones and receptor-blocking chemicals will do that for you right now. Short of that, you'll have to train yourself to never squeed your pelvic floor so it doesn't pump blood to it. Who knows, given time it might atrophe enough to give you the desired effect- good luck holding your pee though