Well, you can write SPRK about their carts containing COTTON or not, and see if you get a different response.
A lot of cart makers state “ALL CERAMIC”, but there are other parts. Metal base, some use glue, oring material, etc.
I had received one broken CCell, so I opened it up just to confirm the cotton, have NOT yet broken open either the SPRK metal or ceramic, I bought both types to try.
I wrote SPRK directly as I was curious since I was thinking of trying to clean them in my ultrasonic cleaner. After the first gram the reclaim byproducts starts to leach back out of the inner atomizer, this is the dark stuff you start to see near the intake holes, and begins to contaminate the fresh oil. One of the main reasons the taste changes on REFILLS. While I’m not TOO cheap, I thought a light ultrasonic cleaning session after a gram or two, might clean out the whole thing. Found some advice online where some claimed success doing this, others cautioned that the cotton would get weak or ruined in a US machine, and that would lead to LEAKING. So far I’ve only put 2 full grams of distillate through each cart, then use a new one. I’m saving the used ones for now. People make claims of getting 2-5 refills, or more. Using on lower power would certainly save some life on the actual COIL, but the oil would get pretty funky refill after refill, in my opinion,
That’s the main reason I wrote them, and they replied that COTTON is used. I don’t have a problem overall with cotton, as I’ve been using it for years when building my own ECig coils. If I ever try some all GLASS carts, I would revisit the US cleaner idea.