I'm using a Biansi Imist - great piece of kit, but I seem to burn up the wicks very quickly and the atomiser is covered in black gun (I'm guessing from using coloured e-liquids). What's the best way to clean it? Is there a cleaning solution I can use that won't damage it (or my lungs!)? At the moment I have to poke a bit of tissue on it to get the excess off but the atomiser is still blackened. What's the best way?