I've tried the organic stuff and it doesn't work for me. Unfortunately, my house and lawn were severely flea infested when I moved in and by the time we figured out the problem, my own furniture had become infested as well.
Puddin had fleas when I got her...fleas are carriers of worm eggs. So if you find fleas, you should deworm immediately.
I use the stuff in the yellow can (they bite the dogs and Nel, but not me) whenever we get a flare up of the little nasties. And I use Advantage on all of the dogs. My attempts to use organic means has only resulted in more frequent recurrences of the outbreaks...the eggs can remain viable more than 7 years, so even if the house has been flea free for years, if there are eggs in the carpets or furniture, they can hatch years later. Maybe my house and garden are too big for organics, I don't know, but I've resigned myself to Advantage and annual sprayings of the lawn, furniture, and carpets.