I bought Füm for a friend and sadly the oils that make up the cores seem to cause his asthma to act up, however he still seems to be finding some success by using it coreless, it's still better than a cigarette or vape.
Don't know if any of this asthma was disclaimed anywhere or not, but would be cool if you guys could find an alternative for the cores, although I'm aware that it's not an easy ask.
Still, great product, and the fidget value alone almost makes up for the asthma part.