? about Knockout and fleas

I adopted two kittens over a month ago and this week at the vet they noticed flea dirt on them. They were both given Frontline and I was told to vacuum with a flea collar in the bag and then throw the bag away. I bought a flea comb and was finding fleas on them days later. I called the vet on Saturday and they gave me a Capstar pill for each and two cans of Knockout fogger to use in my apartment. I moved all the furniture that I could and vacuumed along with using the crevice tool to get along the wall and then gave them their Capstar pills. They told me to wait 30 minutes for the pill to work and then remove them from the apartment. I put them in the car and then went back to set off the foggers. Has anyone else used these products with success? Also the directions on the can did not say what to do after airing out. Should I vacuum again?

The only thing that worked with a flea infestation that I had years ago, (after using the foggers to no avail, as soon as I walked in the fleas were all over me.) first the shag (yes shag) rug was sent out. Then vacuuming all along the crevices with a mothball in the bag. then vet chem flea spray along the crevices (kills fleas and hatched eggs days later). The cats were bathed with vet brand flea shampoo Mycodex, which first lather the neck and then do the rest. The fleas crawl to the top of the foam and die.
AFter that, a maintenance vacuuming and spraying around 10 days later to catch any that may have gotten away. Fleas gone, only one bath for the cats with the correct product.
Never used your product, but I don't think fogging works, waste of time. spraying, vacuuming, and bathing the cats is the answer, and be grateful shag rugs are out of style.