I recently recoiled all of my vivi nova heads with cotton. A 3rd of them got the aforementioned peaches and cream cotton yarn, a 3rd got a thinner crochet yarn, and then I used cheesecloth in a 3rd of them at RPad's recommendation.
So far I'm really impressed with the cheesecloth one, i'm trying to finish off the
juice in my other two vivi novas and try the other two yarns but i don't want to put the cheesecloth one down.
I boiled the whole mess for 20 minutes, incidentally.