I have been using a Burgess propane fogger for three years now. It is strictly for short term mosquito control. If you can find a perfect windless moment it works pretty good for killing the active ones but of course only kills what it touches. The amount of poison you can breathe in from a can of say Black Flag ready mix is very low but should still be avoided when possible. Also be aware that the fog coming out of the nozzle is very hot! It is quite easy to kill bushes, hedges and flowers if they are too close to the nozzle, try to stay 3 feet away. Just FYI, I used beneficial nematodes last year in my yard and flower beds and experienced lower numbers of fleas and mosquitos. I don't know if this was coincidental or not, maybe I can tell you next year.
Scott