Replied by Ted (Bangkok, Thailand)
Borax one tablespoon in one liter of water and water the entire yard. Preferably it may be more effective if the borax one tablespoon is added to a 1% hydrogen peroxide. I will not destroy all of the fleas, but it will kill off most of them, depending on how it is watered on the lawn. A reinfection of the fleas in a dog is best prevented with DEET sprayed twice a day, at 12 hours apart. It's not a perfect one, but it seems to work with me.
