I think that any haunter who has used a store bought fog machine knows the pain these things can be. I have yet to own a fog machine that worked consistently two years in a row, and this isn't by accident, it's a business-minded industrial design tactic called "planned obsolescence" wherein products are designed to fail prematurely in order to encourage consumption.
Consumer fog machines are pretty darn simple, having three basic parts: a reservoir for the fog juice (filtered water and glycerin) a heating element with a thermal regulator to keep the machine from overheating, and a pump to push the fog juice through the system.
If the fellow above could do a makeshift fogger with a Bunsen, a pie tin, and a soda pop bottle, I imagine I could make something pretty effective myself. Heck I could even figure out a condenser so that I wouldn't have to cool the fog to keep it flowin' low, and custom design the output for wider, low-laying, dispersal of the fog.
So I dunno, what do you think? Do you know of anyone who's tried to make their own fog machine?