Moldy Caulk; Cotton ball Method

I have bits of caulk in my shower that are moldy, I had heard of methods of removing it, but I didn't believe it would work.  I have bleached my tub hundreds of times, why would this be any different?  Me, a clean freak, who had scrubbed that caulk for all it was worth, and it wouldn't budge. The cotton ball method as I am calling it, is more for spot treating.  If you have a lot of black caulk this method could become tedious, so, if the other method works, I would do that one.  Spray the area with bleach, shove a cotton ball in there, then soak the cotton ball in bleach.  Leave it there for at least 12 hours, re-soaking the area once in that time frame.  Maybe you could leave it for a shorter amount of time, but since I used my bleach and water mix it might've taken longer.  I would say it cut the severity in half in that spot, but it still needs another round!  The next method I am going to try involves baking soda, bleach, and plastic wrap.  I will use one-hundred percent bleach this next time!  Well, I'm off to do mommy and wifey things, happy cleaning!