Well, ain't none of it good, just degrees of how bad?
Burn oil and gasoline in your saw engine, it makes one trip through and it's gone. Yeah, you breathe some of it, which isn't good. This is also why I won't use leaded fuel, like some people do.
Now instead of running that oil and exhaust through the engine only once and breathing it, instead pull the contaminants out and start concentrating them into a fluid. Do that for thousands and thousands of miles, so you've got the contaminants from a few hundred gallons of gasoline concentrated into that fluid. Now take that fluid, aerosolize it, and breath it in. Ain't going to kill you, hell I've practically bathed in the stuff before, but it's definitely a whole different level of "isn't good". Why the hell would you ever do that on purpose?
Real bar oil is so cheap and so available, there's just zero reason to think this is a good idea. Pack your lunch instead of hitting the drive through window for one day, and you'll have the money to buy a gallon or two of bar oil.
I don't get why this keeps coming up.