*55 gallon metal drum (try industrial sites or the local landfill for a free one)
*32 gallon plastic garbage can
*circular saw with metal cutting blade or a hand saw
*hearing and eye protection
*biohazard sticker or magnet (cheap ones at labsafety.com) or paint and a steady hand
If you don't want to cut the metal you can easily use a hand saw and cut the handles off of the garbage can. I wanted to keep the handles on my garbage can and have access to more barrels so opted to cut the barrel. Put the garbage can on top of the drum. If you plan on having the drum against a wall or in a corner offset the garbage can so that the gap between their rims will allow the fog out toward your guests. Mark where the cuts will have to be made with a marker.