I have no idea how long it takes. I think it varies because there are so many applications to go through. I applied on Dec. 1, got the questions a few days after, and I just got a response today saying that I'm not ready to be a CL.
It varys a lot! I have known some people to get it in a week and other to get it in months. I think the length of time now is increasing due to the sudden splurge of applications. When I applied (back in August) I think I waited a month to become a CL. It took about four days for them to reply and after I replied to them, it took about another four weeks.