Grass is always greener.... if your wife was a slut, you would ask how to get her a religious type. And now you are asking how to make her a slut?
Boy, why dont you get married again? Have two wives of two nature. You would not have a fickle mind to change the same person again and again. Whichever night you want the type, you can.
Or maybe you are lucky, she already is a whore, just pretending till now. Given with a chance she can show you, you are sitting on a gold mine, you can make money by pimping her out.
A man is happy who is content with what he has. Be happy with your wife.