When I was a kid, my dad's preferred parts cleaner was... yep, us kids!
We used gasoline extensively - bearings, crankcases, deposits. Gasoline and a brush. Loosened that 50 year dried on grease loosened and outta there. And yeah, back then, it SMELLED like gasoline. Someone introduced me to the wonder of Gunk Spray-on Degreaser, but it was "expensive, plus you needed to rinse it off with water (and I was taught water = rust). Later we switched to Kerosene as it was "safer" but left a residue (so we'd still rinse in gasoline after cleaaning to get rid of the oily residue)...
At work they made us switch to these water based detergent parts cleaners, but those were flat awful - even heated to near boiling, all they seemed to do was push grease and grime around.
I still use kerosene, but also use brake cleaner and some of these "orange oil" based cleaners that seem to knock it out. I have fond memories of gasoline, but it's not even close to safe, especially any more.