Using naptha for processing ingestibles is not a good idea. Naptha is a cocktail of a lot of different chemicals, none of them a great idea to ingest, and some of them seriously harmful. Even pure actone would be better by comparison (although the acetone that us stoners can buy is not pure). Acetone is a natural metabolite, our bodies make it in small amounts. Trace amounts of it would be unlikely to do harm, unlike trace amounts of, for example, benzene which is just one of the liquid hydrocarbons present in naptha.
Ethanol is the safest, ISO not that far behind, and all hydrocarbons a fair bit behind both of them, IMHO.