You can make an inexpensive dip at home by steeping fresh rosemary in water. Rosemary's scent repels fleas and other insects to keep them from jumping on your dog and hitching a ride inside to infest your house.
How to Make Homemade Flea Dip
Rosemary Flea Dip
Place 2 cups of fresh rosemary in a large pot. Add 1 gallon of water. Place the pot on your stove and turn it on high to bring the contents to a boil.
Reduce the heat to a simmer and allow the contents to steep for approximately 30 minutes.
Turn the stove off and allow the dip to cool until it is lukewarm.
Place a large bowl in your kitchen sink with a colander on top of it. Pour the liquid into the colander to strain the rosemary from the liquid.
Put a funnel in an empty, clean gallon milk jug. Pour the dip into the funnel to fill the milk jug.
Bathe your dog as you normally do. Pour the rosemary dip on your dog to make him thoroughly wet. Allow him to shake the excess off but do not dry him with a towel or blow-dryer. Allow him to air dry naturally.