Need info on flea control

Hi all, I am in need of flea control to prevent Chelsea and Franklin from getting fleas. Here is my problem: when I use stuff like Front Line or Advantage, they act like I'm pouring on boiling acid. They absolutely hate it. I know it's not hurting them since I've gotten it on myself. Also, I check the application area and it is never red nor irritated.
I need to use something so I'm looking for ideas. What brand has the smallest amount of liquid? Maybe if the amount of stuff was less, it would bother them less. I even considered giving them Comfortis until I read about all the nasty side effects.
I'm open to ideas....thanks in advance!

I would use a smaller than prescribed topical amount. I think it DOES cause a reaction on animals, even if we don't have one. :/

I use Vectra. It is given once a month & is comes in a dosage per the cat's weight. My cat is not thrilled with any flea med. They can smell
it from across the room.;)

Well I have tried Advantage,Frontline and a couple more supposidly flea killers. None worked well for me. I have found that giving my cat one capsule of Nitenpyram-same as capstar once a week works better than the aforementioned products. I know you are told even by the vets that you have to use it every day but that is not the case.. It is a heck of a lot cheaper than Capstar and has the same ingredients. I buy mine off Ebay. http://www.ebay.com/sch/i.html?_trks...pyram&_sacat=0