How to find sex on chicks....

I have been wondering how to tell which male or female the chicks are.... until.... last night I watched Discovery Channel (The Dirty Jobs).. The man was showing how to find the sex on chicks. Now I know how to do it. But it's really nasty.. which you had to push the chick to make it pass the poo out! Gross! then open and check if there's bump and shiny.. it mean it's Male. If it's no bump and no shiny.. dull look.. it's female! Get it? LOL I think I am going to try it when I have some more chicks later.. DO it while chicks are few hours old!