Brewer's Yeast works. It has been several years since I had to deal with fleas and I'd forgotten how well it works. I use the nutritional variety (health food store) and if I can't get the powder I use the tablets and grind them up.
After three doses of about a teaspoonful mixed with 3 tablespoons of wet cat food, the fleas didn't just jump off; I am finding a few dead ones in various stages where my cats were laying.
I also called the company that makes the fogger that I also used and the rep suggested a hand-held spray for the closets. I'd already purchased one for hard to reach areas (under the couch and tv stand, beds) and the deck (where it probably started).
Another help is borax mixed with table salt worked into any rugs and left for 48 hours; also check for the eggs and larvae the animals leave behind and combing them at least three times a day. I've learned the hard way that if you live next to the woods or feral animals that your own pets need a flea treatment at least once a month! Or at least comb them a few times a month.