cry it out method not working?

We have been at this since may 22, he sleeps waaay better at night, from 9 to 5am, if he wakes up (hardly ever) he cries himself to sleep again, but it's the fact that whenever I put him in his crib he still cries for like 10 minutes sometimes less. I've tried going in to comfort him but it makes it worse. How long did it take you to accomplish it?