What you have said is right. One need to wait for at-least 30 minutes to get one life in Candy Crush game.
One of my friend, does a trick to solve this issue. He change the time in forward. That means, if you change time 30 minutes forward, you can earn one life instantly. Make sure, to get another life by this method, you have to now be ahead of time you have spent in that life plus 30 minutes. Every time you have to be forward in time to get new lives.
Another way to get more lives when you are out of lives is to ask for life by sending life request to your Facebook friends