O.K. I live on the Wet Coast of Canada (no not a typo). Unlike where Yosemite lives, fleas are a year round problem here. If you are still having problems please PM me. I am sure I can answer any questions you may have.
As Hissy said- please do not apply any more product to these kittens and don't give them any more baths. The application should last for one month and bathing them will not kill the fleas. Are any of the fleas you are getting with the comb still alive??? If not then the product is working. If they are, then either you applied it wrong or your fleas are resistant (not likey). Consider getting a different product from the vet.
Now that the kittens have been treated you need to look at the environment. Pick one day when you have lots of time to clean, preferrably when one or both of your parents have time to help you.
Follow this routine for every room in your house whether or not the kittens have been in it:
1. Strip all the beds and wash all sheets, blankets, and comforters in hot soapy water. Use bleach only when it is safe for the fabric.
2. Wash all pet beds... in hot soapy water.
3. Remove any washable rugs and launder them as well in hot soapy water.
4. Vaccum all the floors, under all the furniture, and in all the crevices. Also vaccum the couch and any chairs. Put cut up flea collars in the vaccum bags and place all used bags outside immediately.
5. Finally if you think you need it, use a premise spray in your house following all the directions. Pay special attention to the corners of the room, and all the nooks and crannies. (You could consider hiring a professional for this step)
If you do this and continue to apply a flea treatment every month you will soon be rid of all the fleas. Keep in mind that the flea has a 6 week life cycle and no one product kills ALL the stages of the life cycle. (In fact there are NO products that kill the coccoon stage) That means that you may still see the occasional live flea for up to 6 weeks after you start to use a flea product. As long as you apply the product every 4 weeks or so any fleas that get into your home from outside or hatch from the environment will die quickly and won't be able to reproduce. Please be patient.