Thanks for these cleaning tips, helpful for anyone who have these and is concerned about using iso.
If I do a non-visual draw I use muscle memory to draw as fast as I normally do. I can feel the vapor, but I want to see it to be sure I'm doing it right. I like most the visual regulation and get the best hits this way. But again, everyone is different, some feel vapor better or learn non-visual techniques more. Laso non-visual are more stealthy.
I can see the vapor in there only when i start drawing when it's accumulated and fades in vortex (so it can be visual regulation for pulse-hitting). I use long slow draw method and this way vapor can be seen only in the stem.
Would like to, maybe next time I will be ordering something big. If I ordered only stems to Europe, I would pay much more only for customs.
If you want vapor try the pulse teqnique rather than the long draw.
As for stems, you shouldn't be paying any customs duty on them as anything under about £20 is exempt. Might want to ask MF to pop them in an envelope rather than send them as a parcel to cut the postage costs.