I have been using the following recipe for the past year on my dogs for fleas and ticks, so far it has worked.
In a spray bottle mix:
8oz. of apple cider vinegar
4 oz. of warm water
1/2 tsp. salt
1/2 tsp. baking soda
I usually spray them down about once a week during flea season.
I also found a recipe on line for homemade dog shampoo, it is supposed to be good for fleas and ticks. I haven't tried it yet but will give it a try for their next bath.
1/4 cup of blue Dawn dish soap
1/4 cup of apple cider vinegar
1/2 cup of warm water
Once you put the shampoo on your dog it says to leave it for 5 minutes and rinse thouroghly