UGH! A little background: I found some flea dirt and a few fleas on my dog in the end of Oct. We treated with Advantix at vet's recommendation and cleaned like crazy people. We're neat freaks to begin with (DH is obsessed with the Dyson) so we clean very often anyway. Since then I've been pretty obsessive with combing him daily with a flea comb and continuing to regularly wash his bedding and stuff. Within 2 weeks of the Advantix, I was still find one or two fleas on him. The vet had me follow up with Capstar (the pill). Since he's a little guy (15-16lbs), she had me give me 1/4 of a tablet two Saturdays in a row. Of course, last week was his last dose and he didn't seem like he had anything on him to begin with.
Then this weekend I noticed some flea dirt again and sure enough DH found 4 fleas when combing.
We haven't seen any on furniture or bedding and neither of us have any bites, so I still think he has a small infestation but I need this to go away before this baby comes. bombing and other dangerous chemicals is OUT of the question (and my DH is an exterminator!)

So once again we're cleaning like freaks today. But since he had both Advantix and capstar I'm not sure what else to do. The vet's closed today, so I'll call tomorrow. I'm going to try bathing him in Dawn today and read about adding Brewer's yeast to his food. I heard it's not a quick fix, but should eventually help.
Anyone try this?

ETA: I didn't use Advantix or Frontline as preventative care before (I'm generally anti-chemicals), but now think I might. Are these monthly treatments? If so, I can repeat, right?