But you don’t need to see fleas to have problems with them. They’re one of the top causes of itching, whereas bathing a dog every two weeks wouldn’t do that.
In some areas, fleas are resistant to Frontline. I’m a bit confused since you mentioned gel, and both Frontline and Advantage/Advantix are clear liquids.
If you’re using Frontline (or Frontline plus), as advised (and it can be used up to twice a month), and you’re still seeing fleas, then I’d go for Advantage/Advantix (make sure you get the right size for the dog). Alternatively, you can go to the vet and get some of the other potent, newer products (Advantage Multi, Promeris, Comfortis, etc.) that still require prescription.
Don’t treat the dog between baths, treat the dog after its been washed and dried.
Again, if you go to the pet store and get Capstar (appropriate size), that can control the fleas while the Advantage kicks in.
Really, there should be a sticky or something, since this topic comes up every month. Again, OTC products, flea baths, flea collars, for the most part, are ineffective. There are now two good products (depending on your area) that used to be prescription only, that are more expensive but worth it (unless you live in an area with Frontline-resistant fleas). Paying all that money for baths, OTC things that don’t work… really, you’d use the money better by going to the vet and/or getting the products that work.
If, after all these, the dog is still itching, then you may eventually have to really see the vet because it may be some other type of allergy. But attack the fleas first!