I crate trained Cody and for the most part it is very effective. Just as long as you start it when they are a pup. It seems to have worked with these dogs too though, and they were adults. It is a VERY effective way to house train a puppy. Cody caught on very quickly. Dogs will not soil their bed and if you keep the crate small enough they will hold it in. But you must not allow them to hold it in for too long.