I think many books and such that give tips on spicing it up are just full of suggestions. No book that I have seen tells you that you HAVE to do what it says. Most books are just collections of ideas. A couple can decide which ideas they'd like to try, and then they can easily find more information on those ideas.
Many couples have difficulty thinking of new ideas; a lot of the time when you're getting bored of the sex, it's because you've tried all the stuff you can think of. It's not a crime to look to sources other than your own imagination.
And this is in the vibrator section. It would probably fit better in Spicing Up a Marriage or something.