Boiling can sterilize and remove some substances, but it can also just cook some onto the wick. Example: Soak your wicks in some beaten egg and boil them, you get wick with poached egg in them. The best is to wash all wicks thoroughly with a good dish detergent before boiling, I rub the detergent into the wick material and rinse under the faucet several times, repeating this until I feel confident it is clean. You will be surprised how much crap comes out of SS, hemp and other wick material. After a good washing, boiling or steam cleaning is good.