|If only there was a CB with bio-feedback like in my novel!|
Sure, if she likes the idea of holding the key, that's different. However, if your chastity is really about you being chaste/neutered-lite, then the key itself is just another responsibility for her.
Better to use timed encryption software to do the job. This isn't as much of a fiddle as it sounds:
How to use encryption software to timelock your chastity beltBuy a combination padlock and learn how to set the combination without looking.
Each time you enjoy a period of lockup, set the combination, scan it into your PC, then encrypt the image.
Easy? What about the encryption software
Free timed encryption software for chastity belt useThere are several free programs knocking around. The one I've now started using is PictureLoKiT, which is not only free, it's also straightforward to use. (I'd still rather have an actual keysafe, though...)
MORE COMPLETE INSTRUCTIONS HERE.