Yup reduces vapor and flavor and bad or burnt taste. Thicker liquids will gunk them up faster because the holes that the liquid gets drawn in to are really small. And because the wick wrap it has to go through to get to the actual coil. I usually set some aside and wait until I have a few and soak them in everclear, vodka or Poledent and let them dry for a day or so. Some times they clean up nice and sometimes they don't.