+1 for cotton....balls or yarn. I haven't used anything else in months. I even use it in all my gennys. I boiled the first batch and my mind keeps telling me it tasted better. I keep meaning to boil again but I keep forgetting. Unboiled tastes and performs really well. I only use the yarn in my ithaka. Cotton balls for everything else. I never boiled the yarn. Something tells me that would make ita pain.