There is a lot of rubbish being written in various adverts stating how "this fogger super heats the smoke which then kills any bacteria causing the odour" Don't be sucked in by this rubbish.
Thermal foggers work by super heating either a water or Glycol based fluid with properly formulated deodourisers. The resulting smoke then penetrates every little nook and cranny coating all the odour pockets (microscopic pores in materials) with a fine coating of the fluid. This goes some way towards eradicating bad odours. They do not and cannot kill bacteria unless you were using an actual product designed for this and for use in thermal foggers, I do not know of one. You would also need to be wearing breathing apparatus when using it.
It is not a cure all and really bad smells can return (smoke, tobacco, rotten meat etc). Restoration contractors use them, but only as part of a complete system.
Also the critical part of these foggers is the heating element. A lot of what I have seen advertised lately are designed for the Halloween Effects market or Disco market. Some of the more expensive disco models are quite good. The cheaper ones are not very good and don't stand up to the rigours of commercial cleaning use. Some of the fluids being supplied are also nothing more than perfumed water. Professional fluids which have been specially developed for fire and odour restoration cost anywhere from £30-40 bottle.
