It's really not your fault! The problem with Frontline and the others that are sold OTC is that they are both more toxic to the pet and less effective on the fleas--maybe because the products aren't continually developed so the fleas do become immune. There was also an issue a few years ago with counterfeit products showing up on the market, and I'm not sure that was solved. Revolution is made by Pfizer and continually "tweaked"; my animals have been on it for over 10 years, both cats and dogs, and never had a bad reaction, nor a renewed flea problem. It costs about $50 for a 3 month supply. Varies a bit depending upon whether it's for cat or dog (not interchangeable) and size of animal. My vet charges $20 a month, but they undercharge on so many services that I figure they deserve a bit of profit on the sale.

The pest people told me that they can only treat areas they can get to directly which is why the emptier the better. They didn't use bombs; I think they used handheld sprayers so they could really get into all the nooks and crannies (my house has plenty!) I don't remember how long before I could move in but it wasn't long. I don't know what they do special with furniture and carpets, but I imagine they have a way of tenting them for treatment. I don't think fleas penetrate upholstery except through open spaces, like a torn lining. They get into the seams, but that's reachable.

Cardboard boxes are a magnet for fleas laying eggs, though.

I don't have a problem in my yard, but my friends who live a couple of miles away have periodically had fleas in the grass problems. It really depends on seasonal weather and the terrain; they also get a lot of deer on their land that I don't have.

But I would really talk with your vet about options, especially as your pets have been exposed to a variety of flea treatments. They can recommend the proper transition schedule that will work and be safe for them. They have a couple of other options not available to groomers that can be given as a one time eradicator before starting a monthly schedule, too. There's hope!