I use Kerosene , I don't use the electric pump or smoke near it.
I was recently considering sealing off the pump hole just to keep all the fumes in check.
I also add carb cleaner, brake clean ( and everything else that cleans) into the mix every time I clean something. So right now it's cleaning parts very well, probably toxic as hell, and a real health risk....But I figure that I'll be effected by all the aluminum oxides and have Alzhiemer's long before the cancer can kill me.
I really hate dirty parts.
I'm sure someone here uses something safer.