I haven’t tried flea bombs. I was under the impression that you had to vacate the house for a lot longer than just a couple hours. Also, the idea of re-doing it periodically to get the newly hatched eggs. It would be hard to get the cats all outside on the patio, invading the space of the ones that live there, it would take all of my energy just to supervise them there - of course de-fleaing all of them beforehand. Not to mention getting the spouse to leave the house for that long. LOL But if it can be done in 2 hours, I may research it further!
Any insecticide other than pyrethum (sp?) is very toxic to humans. And animals. One thing that is extremely useful to prevend flea infestations is removing all carpets. Wood, tile, etc floors are not flea habitats. Much easier to get rid of them with cleanable floors.