What does matter is that if it works for me, it might just work for you too. Just because you repel fleas, doesn't mean that there won't be any. If our dogs go hunting and are down in a fox den, the come out covered in fleas. These have to be dealt with immediately to prevent the fleas from infesting the rugs or furniture. You need to have a flea comb and regularly look for any renegade fleas that might have managed to avoid the repellent.
Flea combs are very inexpensive and very effective at trapping the little guys.
I have several in various rooms of the house so that I can regularly comb through the dogs' fur to investigate. The first thing to do if your dog has been exposed to a large number of fleas is to bathe the dog thus drowning the fleas. It won't provide any residual effect, however, so if you can get hold of some flea shampoo, so much the better. I would try for a herbal one myself, but you have to sometimes take what you can get. If at home and bathing isn't possible, you can make up Lemon Skin Tonic.