SoFlaNative.....The propane fogger is the smaller..I use "ExciteR" which is 6% Pyrethrins and 60% piperonyl Butoxide, technical...That needs to be diluted with ULV oil...The "ExciteR" oil can be bought from various vendors..Just google ExciteR...Much, much better stuff than that Blackflag stuff
On one of those prolane foggers, the one thing I've found about using it is to be sure to let it furn after for a couple of minutes until no more fog come out...The pump should be cleaned out with rubbing alcohol..Propane doesn't need to be lit.
The thermal fogger, is basically a WWII German V2 pulse jet on a smaller scale..It's more of a commercial machine..It can be hand carried, but it is big..It puts out almost triple fog that the propane will. I mount mine to a small 2 wheel wagon, and pull it behind my rider mower.
In the photo I attached, that is my big fogger...I do suit up with PPE when I use it.
One that still pops up from time to time for sale is the type that one would be adapted to attach to the exhaust of a lawn mower...Those were more of back in the early 50's when DDT could be used.
WuzzFuzz