Do you think a book of tips for guys to get their wives to want to have more sex with them would sell? It would have a lot of new and/or different things that a lot of people haven’t heard of before, not the same old cliches.
Thoughts appreciated. Unless, of course, they’re stupid. 
It depends on the types of tips. If you tell men that a woman who is overtired is not going to be that interested in sex, and if they do more of what their wives are doing around the house (or hire a housekeeper), then no, it probably won’t sell, even though it’s true.
Tell people (men AND women) what they want to hear, what they want to believe, and it’ll sell, even if you’re lying through your teeth.
Will it come with a fake jacket so that the book appears to wives to be about football or such?
I think it would sell but not necessarily get read. When guys finish the first chapter and realize that there are not magic words or elixirs that will make their wives more compliant, they will lose interest.
AFAICT men are not into ‘fixing’ relationships. Women are really big into ‘fixing’ problem relationships. Look at the “relationship” section in the bookstore and it is devoted towards Women fixing things.
If you marketed it correctly it might sell – someone has made a good living selling men on the idea that they can have any women they want instantly through some form of hypnosis. Probably a lot of married men would fall for the same scam in regard to their wives.
Because what you’re proposing is a scam. There are books for couples to improve their sex lives, by communicating better or trying new things or whatever–the key to these is that both partners are involved and working together. There are loads of self-improvement books on every topic (I suspect women are the primary buyers except for books on business success). But what you’re suggesting is a book to tell you how to improve someone else.
If you offered a book on how to be a more thoughtful, more attractive husband in order to have more and better intimacy with your wife, then no, men wouldn’t buy that book.
So you want to write a book on the same topic that every single men’s magazine runs a monthly article on?