Usually, the spouse who ends up here is fighting for his/her marriage, and the other spouse has checked out, is having an affair, is in a mid-life crisis, etc. In any of those circumstances, they've going to see the overt suggestion that they need to work on the marriage as pressure, which is going to drive them further away.
In reality, the information offered by those books teaches readers how to become better people, and therefore how to be the partner their spouse has been looking for. It's better to wait until that process has been finished (and the walkaway spouse has noticed the changes) before revealing the self-help book behind it.
Moreover, there's no point talking about a book meant to improve the marriage until both partners are ready and willing to work on the marriage. Once open communication has been established, then the love-busting spouse can check whether the returning walk-away is interested in the information in DR or DB.
Don't think of any of the changes you are making as "secrecy." Generally, once people come here, it's because their spouses have a lot of secret liasons, etc, that they're not sharing. Think of the books as a private coping strategy that will get you to the point where you're able to communicate with your spouse.
It might help to explain your situation, so that you can get suggestions tailored towards it. Also, try to stick to one thread, so people know where to look for you--those with a whole lot of threads tend to get dropped.
