For small engines with carburetors, you can just squirt the fogger into the carb while it's running till it smokes a lot and then let it idle and squirt till it stalls. Good for seasonal equipment, marine, ATV's, snowmobiles etc. Don't put the fogger through fuel injection systems, it can cause issues.
And, for cars, check that the fogger solution is catalytic converter friendy.
And, for cars, check that the fogger solution is catalytic converter friendy.