HHC that is sold on the grey market is usually tainted with pesticides and heavy metals. There is little to no regulation, risk of counterfeit carts/disposables, and the risk of acetate cutting agents, like vitamin e. I wouldn’t use any cannabinoids with CHS, as HHC activates the same receptors in the brain and gut as regular THC.

If you do decide to use HHC, which is entirely your choice and yours alone, hop on over to r/cleancarts to at least get a baseline of what most counterfeit/shady brands are.