Anyone know of a guide for a keyholder focusing solely on pure male chastity?

Most of what I’ve come across has been kinky dom/sub content that happens to involve chastity. They are almost always focused on teaching the man how to obey his new kinky slut wife, who holds the key. I have only found two books aimed at vanilla chastity, and even those cover all the things a guy needs to do to make it work in a relationship. Does anyone know of a guide for women that will help her be a better keyholder without telling her she needs to turn her husband into a woman and start dating black men? We bought the male chastity guide for keyholders, but it was geared toward people just getting their feet wet with chastity and didn’t touch on anything helpful for experienced players. If you know of any books, blogs, websites or other resources that help one be a better keyholder, please share.