I still need to try out some Rayon in mine, Haven't done that as of yet due to still testing out the longevity of KGD as wicking material. I get 70-80ml's in my 22mm Siren before I need to re-wick (that's when I get that slight OFF taste that tells me a change is in order). Next up, Rayon I think, and I'll just add a little KGD to the wick ports to prevent any leaks.