From what I've read the sterile cotton doesn't need to be boiled, but then I am assuming if it's white it's been bleached so maybe it does.
I ran all over town to find organic cotton because that's the big buzz online. I found a big bag at CVS and was psyched. I got home and was reading a post talking about bleach or hydrogen peroxide being used by companies to make the cotton white. Sure enough my bag says it's been bleached with hydrogen peroxide. I plan to boil it just to be sure there is nothing in it I don't want to taste. I don't know if I need to or not but I'm going to anyway.
On a side note, think of all the processed and unnatural foods most of us eat with little care or worry, but we are boiling cotton balls to be safe. Maybe I should start boiling my ring dings and oreos too?