Hijacking the thread here, but I would have to respectfully disagree with that one. In my vast experience with literally thousands of dogs, NO soap or detergent will get rid of fleas and ticks. They will simply be squeaky clean like the dog. You might successfully wash away some of the adults but not all, and not the eggs stuck to the hairs. It is a short hatch later and the animal is covered again.
Stick to the chemical treatments to clear those critters or if you want a natural treatment i sweat by Diatomaceous Earth (DE) for killing fleas and ticks, it's not instant but within a few days they are all gone and it does the eggs too. The great thing is the ability to powder their bedding, house, your home and anything else that needs treated and then just vacuum it up after a few days or a week. We used it on dogs, horses, cats, the house, kid's headlice .. any thing and every thing with more than 4 legs got powdered.
I would make dog soap with DE in it if I thought the DE would still be effective after getting wet. Something to research there.