Kerosene is also a hydrocarbon solvent, isn' t necessarily bad. It just seems to have a higher boiling point and maybe some aromatic hydrocarbons mixed in, which means it will probably also be less selective towards the alkaloids and not freeze precipitate well.

But you could easily enough salt out the alkaloids from the kerosene and then rebasify and crystallize in any number of ways, kidna like you would if you were using limonene or whatever (check BLAB tek for an example).