Anyone have a good idea for making a smoke machine?

My car is 15 years old, and the buna is getting old and tired but they
don't make a single kit of all the rubber parts which would be the easy way
to avoid making my own smoke tools.

I keep getting a P0171/P0174 (bank 1 and 2 lean condition), which, for my
engine, almost always means a crack in the complex hoses, tubes, and pipes,
so I want to see if I can build my own smoke machine for about the cost of
one diagnostic test by the pros.

A single professional smoke test is about $150 based on a dozen calls today
(where most charge a flat diagnostic fee). And the dealer price for
replacing all the hoses is estimated at far more than that one test.

I don't want to debate those two points here though (the pro diagnostic or
replacing all the rubber) because my intent here is to ask for advice on
building my own smoke machine for about one hundred dollars.

Just generating smoke is easy with a diesel glow plug shoved into a paint
can with glycerin in it, but you have to generate dense smoke and you have
to pump it under a few psi through the engine hoses.

Have you built your own smoke machine for around $100 or less?
How did you do it?